BARRETT RESOURCES CORP
S-4, 1995-06-09
PETROLEUM & PETROLEUM PRODUCTS (NO BULK STATIONS)
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<PAGE>
 
     As filed with the Securities and Exchange Commission on June 9, 1995
                                                            Registration No. 33-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C.  20549
                             --------------------  

                                    FORM S-4
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                             --------------------  

                         BARRETT RESOURCES CORPORATION
             (Exact name of Registrant as specified in its charter)

     Delaware                     1311                         84-0832476
  (State or other      (Primary Standard Industrial         (I.R.S. Employer
  jurisdiction of       Classification Code Number)      Identification Number) 
 incorporation or                                              
   organization)

                      1125 Seventeenth Street, Suite 2400
                            Denver, Colorado  80202
                                (303) 297-3900
   (Address, including zip code, and telephone number, including area code,
                 of Registrant's principal executive offices)

                       Donald H. Stevens, Vice President
                         Barrett Resources Corporation
                      1125 Seventeenth Street, Suite 2400
                            Denver, Colorado  80202
                                (303) 297-3900
           (Name, address, including zip code, and telephone number,
                  including area code, of agent for service)
                             --------------------  

                                  Copies to:
    John W. Carr, Esq.          Alan L. Talesnick, Esq.     Thomas A. Cole, Esq.
Simpson Thacher & Bartlett    Bearman Talesnick & Clowdus     Sidley & Austin 
   425 Lexington Avenue         Professional Corporation         One First 
New York, New York  10017     1200 Seventeenth Street,         National Plaza  
     (212) 455-2000                   Suite 2600              Chicago, Illinois 
                               Denver, Colorado 80202               60603
                                   (303) 572-6500               (312) 853-7000
                                
 Approximate date of commencement of proposed sale to the public:  As promptly
as practicable after this registration statement becomes effective.

 If the securities being registered on this Form are to be offered in connection
with the formation of a holding company and there is compliance with General
Instruction G, check the following box: [_]
                             --------------------  

                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
============================================================================================================
 Title of Each Class of                       Proposed Maximum        Proposed Maximum      
    Securities to be       Amount to be      Offering Price Per      Aggregate Offering        Amount of    
       Registered          Registered(1)          Share(2)                 Price(2)         Registration Fee 
- ------------------------------------------------------------------------------------------------------------
<S>                        <C>               <C>                     <C>                    <C>
Common Stock, par           13,425,071            $26.6875                 $275,601,225         $95,035(3)
 value $.01 per share....
============================================================================================================
</TABLE>
 (1)  The number of shares of Common Stock, par value $.01 per share ("Barrett
      Common Stock"), of the Registrant to be registered is based upon (i) the
      maximum number of shares of Common Stock, par value $.01 per share
      ("Plains Common Stock"), of Plains Petroleum Company, a Delaware
      corporation ("Plains"), that will be converted into shares of Barrett
      Common Stock in the Merger (as defined in the enclosed Joint Proxy
      Statement/Prospectus) plus (ii) shares of Plains Common Stock subject to
      outstanding stock options of Plains, which, following the Merger, will
      constitute options to purchase shares of Barrett Common Stock plus (iii)
      shares of Plains Common Stock that may be issued pursuant to Plains
      benefits plans ("Fully Diluted Plains Stock"), multiplied by 1.3, the
      Exchange Ratio (as defined in the enclosed Joint Proxy
      Statement/Prospectus) in the Merger.

(2)   Estimated solely for the purpose of calculating the registration fee
      pursuant to Rule 457(f) under the Securities Act of 1933, as amended (the
      "Securities Act"). Based on a price of $26.6875 per share of Plains Common
      Stock, the average of the high and low prices of the Plains Common Stock
      as reported on the New York Stock Exchange Composite Tape on June 2, 1995,
      multiplied by the number of shares of Fully Diluted Plains Stock.

(3)   A fee of $70,293.38 was paid on May 25, 1995 pursuant to Section 14(g) of
      the Securities Exchange Act of 1934, as amended, and Rule 0-11 thereunder
      in connection with the filing by the Registrant and Plains of joint
      preliminary proxy materials for use in respect of the Merger. Pursuant to
      Rule 457(b) under the Securities Act, and Section 14(g) of the Exchange
      Act and Rule 0-11 thereunder, the amount of such previously paid fee has
      been credited against the registration fee payable in connection with the
      filing of this Registration Statement. Accordingly, the remainder of the
      filing fee of $24,741.62 is being paid with the filing of this
      Registration Statement.

   The Registrant hereby amends this Registration Statement on such date or
dates as may be necessary to delay its effective date until the Registrant shall
file a further amendment which specifically states that this Registration
Statement shall thereafter become effective in accordance with Section 8(a) of
the Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.
================================================================================
<PAGE>
 
                             CROSS-REFERENCE SHEET

                   Pursuant to Item 501(b) of Regulation S-K
             Showing the Location in the Proxy Statement/Prospectus
               of the Information Required by Part I of Form S-4
<TABLE> 
<CAPTION> 
            Form S-4 Item               Location in Proxy Statement/Prospectus
            -------------               --------------------------------------

                      A. Information About the Transaction
<S>                                     <C>   
1.  Forepart of Registration Statement 
     and Outside Front Cover Page of    
     Prospectus.......................  Outside Front Cover Page
 
2.  Inside Front and Outside Back 
     Cover Pages of Prospectus........  Table of Contents; Available 
                                        Information; Incorporation of Certain
                                        Documents by Reference

3.  Risk Factors, Ratio of Earnings to 
     Fixed Charges and Other 
     Information......................  Summary 
 
4.  Terms of the Transaction..........  Summary; Introduction; The Special
                                        Meetings; The Merger; Certain
                                        Provisions of the Merger Agreement;
                                        Comparison of Rights of Holders of
                                        Plains Common Stock and Barrett
                                        Common Stock
 
5.  Pro Forma Financial Information...  Summary; Unaudited Pro Forma 
                                        Consolidated Condensed Financial
                                        Statements
 
6.  Material Contacts with the
     Company Being Acquired...........  The Merger
 
 
7.  Additional Information
     Required for Reoffering by          
     Persons and Parties Deemed to be
     Underwriters.....................  Not  Applicable
 
 
8.  Interests of Named Experts          
     and Counsel......................  Experts; Legal Opinions
 
9.  Disclosure of Commission
     Position on Indemnification for
     Securities Act Liabilities.......  Not Applicable
 
<CAPTION>  
                      B.  Information About the Registrant
<S>                                     <C>   

10. Information with Respect to         
     S-3 Registrants..................  Available Information; Incorporation
                                        of Certain Documents by Reference;  
                                        Summary; Barrett Resources          
                                        Corporation; Post-Merger Profile and
                                        Strategy; Security Ownership of     
                                        Management and Certain Beneficial   
                                        Owners; Description of Capital Stock
                                        of Barrett; Comparison of Rights of 
                                        Holders of Plains Common Stock and  
                                        Barrett Common Stock                 

11. Incorporation of Certain
     Information by Reference.........  Incorporation of Certain Documents by
                                        Reference

12. Information with Respect to S-2
     or S-3 Registrants...............  Not Applicable
 
 
13. Incorporation of Certain
     Information by Reference.........  Not Applicable
 
 
14. Information with Respect to
     Registrants Other than S-3 or S-2   
     Registrants......................  Not Applicable 

<CAPTION>  
                C. Information About the Company Being Acquired
<S>                                     <C>   

15. Information with Respect to         
     S-3 Companies....................  Available Information; Incorporation
                                        of Certain Documents by Reference;  
                                        Summary; Plains Petroleum Company;  
                                        Post-Merger Profile and Strategy;   
                                        Security Ownership of Management and
                                        Certain Beneficial Owners;          
                                        Description of Capital Stock of     
                                        Plains; Comparison of Rights of     
                                        Holders of Plains Common Stock and  
                                        Barrett Common Stock; Certain       
                                        Litigation                           

16. Information with Respect            
     to S-2 or S-3 Companies..........  Not Applicable 
 
17. Information with Respect to
     Companies Other Than S-2 or S-3     
     Companies........................  Not Applicable 

<CAPTION>  
                      D. Voting and Management Information
<S>                                     <C>   

18. Information if Proxies,
     Consents or Authorizations are to  
     be Solicited.....................  Outside Front Cover Page; Available  
                                        Information; Incorporation of Certain
                                        Documents by Reference; Summary;     
                                        Introduction; Post-Merger Profile and
                                        Strategy; The Special Meetings; The  
                                        Merger; Unaudited Pro Forma          
                                        Consolidated Condensed Financial     
                                        Statements; Certain Provisions of the
                                        Merger Agreement; Certain Litigation  

19. Information if Proxies,
     Consents or Authorizations are 
     not to be Solicited in an 
     Exchange Offer...................  Not Applicable 
</TABLE> 
 
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
                            1125 SEVENTEENTH STREET
                                   SUITE 2400
                             DENVER, COLORADO 80202
 
                                                                   June 13, 1995
 
Dear Barrett Resources
 Corporation Stockholder:
 
  You are cordially invited to attend a Special Meeting of Stockholders of
Barrett Resources Corporation ("Barrett"), which will be held at the Brown
Palace Hotel, 321 Seventeenth Street, Denver, Colorado, at 11:00 a.m., Denver
time, on Tuesday, July 18, 1995.
 
  At the Special Meeting, you will be asked to approve certain matters related
to the proposed merger (the "Merger") of Barrett Energy Inc., a wholly owned
subsidiary of Barrett ("Sub"), with and into Plains Petroleum Company
("Plains"), which will result in Plains becoming a wholly owned subsidiary of
Barrett. Specifically, you will be asked to approve the following:
 
    (1) an amendment to Barrett's Certificate of Incorporation to increase
  its authorized Common Stock from 17,000,000 shares to 35,000,000 shares
  (the "Charter Amendment"); and
 
    (2) the issuance of shares of Barrett's Common Stock (the "Stock
  Issuance") in connection with the Agreement and Plan of Merger (the "Merger
  Agreement") among Barrett, Sub and Plains, including the issuance of shares
  of Barrett Common Stock in the Merger and the reservation of shares of
  Barrett Common Stock for issuance upon exercise of certain stock options of
  Plains which, following the Merger, will constitute options to purchase
  Barrett Common Stock.
 
Pursuant to the terms of the Merger Agreement, each outstanding share of Common
Stock of Plains will be converted into 1.3 shares of Common Stock of Barrett.
Cash will be paid in lieu of fractional shares of Barrett Common Stock.
 
  The effect of your approval will be to enable Barrett to complete the Merger
with Plains. The Merger is described in the accompanying Joint Proxy
Statement/Prospectus, which includes a summary of the terms of the Merger and
certain other information relating to the proposed transaction.
 
  THE BOARD OF DIRECTORS OF BARRETT HAS DETERMINED THAT THE MERGER IS FAIR TO
AND ADVISABLE AND IN THE BEST INTERESTS OF THE HOLDERS OF SHARES OF BARRETT
COMMON STOCK. ACCORDINGLY, THE BOARD HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT AND THE MERGER, INCLUDING THE CHARTER AMENDMENT AND THE STOCK
ISSUANCE, AND RECOMMENDS THAT YOU VOTE IN FAVOR OF THE CHARTER AMENDMENT AND
THE STOCK ISSUANCE AT THE SPECIAL MEETING.
 
  A Notice of the Special Meeting and a Joint Proxy Statement/Prospectus
containing detailed information concerning the Merger and related transactions
accompany this letter. We urge you to read this material carefully.
 
  Your vote is very important. Please mark, date, sign and return the enclosed
proxy in the enclosed postage prepaid envelope as soon as possible, regardless
of whether you plan to attend the meeting. If you have any questions regarding
the proposed transaction, please call Corporate Investor Communications, Inc.,
our proxy solicitation agent, toll free at (800) 242-4410 or collect at (201)
896-1900.
 
  Thank you. We look forward to seeing you at the meeting.
 
                                          Sincerely,
 
                                          William J. Barrett
                                          Chairman and Chief
                                          Executive Officer
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
                            1125 SEVENTEENTH STREET
                                   SUITE 2400
                             DENVER, COLORADO 80202
 
                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                          TO BE HELD ON JULY 18, 1995
 
Dear Stockholder:
 
  A Special Meeting of Stockholders of Barrett Resources Corporation
("Barrett") will be held at the Brown Palace Hotel, 321 Seventeenth Street,
Denver, Colorado, at 11:00 a.m., Denver time, on Tuesday, July 18, 1995 to
consider and vote upon the following matters in connection with the Agreement
and Plan of Merger, dated as of May 2, 1995 (the "Merger Agreement"), which
appears as Annex I to the accompanying Joint Proxy Statement/Prospectus,
providing for the merger (the "Merger") of Barrett Energy Inc., a wholly owned
subsidiary of Barrett, with and into Plains Petroleum Company ("Plains"):
 
    (1) the approval of an amendment to Barrett's Certificate of
  Incorporation to increase its authorized Common Stock from 17,000,000
  shares to 35,000,000 shares (the "Charter Amendment");
 
    (2) the approval of the issuance of shares of Common Stock of Barrett
  (the "Stock Issuance") in connection with the Merger Agreement, including
  the issuance of shares of Barrett Common Stock in the Merger and the
  reservation of shares of Barrett Common Stock for issuance upon exercise of
  certain stock options of Plains which, following the Merger, will
  constitute options to purchase Barrett Common Stock; and
 
    (3) the transaction of such other business, if any, as may properly come
  before the Special Meeting or any adjournments or postponements thereof.
 
  The Board of Directors of Barrett has fixed the close of business on June 13,
1995 as the record date for the determination of Barrett stockholders entitled
to notice of and to vote at the Special Meeting.
 
  The approval of the Charter Amendment requires the affirmative vote of a
majority of the outstanding shares of Barrett Common Stock. The approval of the
Stock Issuance requires the affirmative vote of a majority of the votes cast on
the proposal, provided that the total votes cast on the proposal represent a
majority of the outstanding shares of Barrett Common Stock entitled to vote
thereon.
 
  YOUR VOTE IS VERY IMPORTANT. PLEASE MARK, DATE AND SIGN THE ENCLOSED PROXY
CARD AND RETURN IT PROMPTLY IN THE ENCLOSED POSTAGE PREPAID RETURN ENVELOPE,
REGARDLESS OF WHETHER YOU EXPECT TO ATTEND THE MEETING. IF YOU SIGN AND RETURN
YOUR PROXY CARD WITHOUT SPECIFYING HOW YOU WOULD LIKE YOUR SHARES VOTED, IT
WILL BE UNDERSTOOD THAT YOU WISH TO HAVE YOUR SHARES VOTED FOR THE CHARTER
AMENDMENT AND THE STOCK ISSUANCE. YOU MAY REVOKE YOUR PROXY BY SIGNING AND
RETURNING A LATER DATED PROXY WITH RESPECT TO THE SAME SHARES, BY FILING WITH
THE SECRETARY OF BARRETT A DULY EXECUTED REVOCATION, OR BY ATTENDING THE
SPECIAL MEETING AND VOTING IN PERSON (ALTHOUGH ATTENDANCE AT THE SPECIAL
MEETING WILL NOT IN AND OF ITSELF CONSTITUTE A REVOCATION OF YOUR PROXY).
 
                                          By order of the Board of Directors,
 
                                          J. Frank Keller
                                          Secretary
 
Denver, Colorado
June 13, 1995
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
                            12596 WEST BAYAUD AVENUE
                                   SUITE 400
                            LAKEWOOD, COLORADO 80228
 
                                                                   June 13, 1995
 
Dear Plains Petroleum
 Company Stockholder:
 
  You are cordially invited to attend a Special Meeting of Stockholders of
Plains Petroleum Company ("Plains"), which will be held at the Brown Palace
Hotel, 321 Seventeenth Street, at 9:00 a.m., Denver time, on Tuesday, July 18,
1995.
 
  At the Special Meeting, you will be asked to approve and adopt an Agreement
and Plan of Merger (the "Merger Agreement") providing for the merger (the
"Merger") of Barrett Energy Inc., a wholly owned subsidiary of Barrett
Resources Corporation ("Barrett"), with and into Plains, which will result in
Plains' becoming a wholly owned subsidiary of Barrett. Pursuant to the terms of
the Merger Agreement, each outstanding share of Common Stock of Plains will be
converted into 1.3 shares of Common Stock of Barrett. Cash will be paid in lieu
of fractional shares of Barrett Common Stock.
 
  The effect of your approval will be to enable Plains to complete the Merger.
The Merger is described in the accompanying Joint Proxy Statement/Prospectus,
which includes a summary of the terms of the Merger and certain other
information relating to the proposed transaction.
 
  THE BOARD OF DIRECTORS OF PLAINS HAS DETERMINED THAT THE MERGER AGREEMENT AND
THE MERGER ARE FAIR TO AND ADVISABLE AND IN THE BEST INTERESTS OF THE HOLDERS
OF SHARES OF PLAINS COMMON STOCK. ACCORDINGLY, THE BOARD HAS UNANIMOUSLY
APPROVED THE MERGER AGREEMENT AND THE MERGER, AND RECOMMENDS THAT THE HOLDERS
OF SHARES OF PLAINS COMMON STOCK VOTE IN FAVOR OF THE MERGER AGREEMENT AND THE
MERGER AT THE SPECIAL MEETING.
 
  A Notice of the Special Meeting and a Joint Proxy Statement/Prospectus
containing detailed information concerning the Merger and related transactions
accompany this letter. We urge you to read this material carefully.
 
  Your vote is very important. Please mark, date, sign and return the enclosed
proxy in the enclosed postage prepaid envelope as soon as possible, regardless
of whether you plan to attend the meeting. If you have any questions regarding
the proposed transaction, please call D.F. King & Co., Inc., our proxy
solicitation agent, toll free at (800) 290-6431 or collect at (212) 269-5550.
 
  We look forward to seeing you at the meeting.
 
                                          Sincerely,
 
                                          James A. Miller
                                          Chairman and Chief Executive Officer
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
                            12596 WEST BAYAUD AVENUE
                                   SUITE 400
                            LAKEWOOD, COLORADO 80228
 
                   NOTICE OF SPECIAL MEETING OF STOCKHOLDERS
                          TO BE HELD ON JULY 18, 1995
 
Dear Stockholder:
 
  A Special Meeting of Stockholders of Plains Petroleum Company ("Plains") will
be held at the Brown Palace Hotel, 321 Seventeenth Street, Denver, Colorado, at
9:00 a.m., Denver time, on Tuesday, July 18, 1995 to consider:
 
    (1) the approval and adoption of an Agreement and Plan of Merger, dated
  as of May 2, 1995 (the "Merger Agreement"), which appears as Annex I to the
  accompanying Joint Proxy Statement/Prospectus, providing for the merger
  (the "Merger") of Barrett Energy Inc., a wholly owned subsidiary of Barrett
  Resources Corporation ("Barrett"), with and into Plains; and
 
    (2) the transaction of such other business, if any, as may properly come
  before the Special Meeting or any adjournments or postponements thereof.
 
  The Board of Directors of Plains has fixed the close of business on June 13,
1995 as the record date for the determination of stockholders entitled to
notice of and to vote at the meeting.
 
  The affirmative vote of the holders of a majority of the outstanding shares
of Common Stock of Plains is required to approve and adopt the Merger Agreement
and the Merger.
 
  YOUR VOTE IS VERY IMPORTANT. PLEASE MARK, DATE AND SIGN THE ENCLOSED PROXY
CARD AND RETURN IT PROMPTLY IN THE ENCLOSED POSTAGE PREPAID RETURN ENVELOPE,
REGARDLESS OF WHETHER YOU EXPECT TO ATTEND THE MEETING. IF YOU SIGN AND RETURN
YOUR PROXY CARD WITHOUT SPECIFYING HOW YOU WOULD LIKE YOUR SHARES VOTED, IT
WILL BE UNDERSTOOD THAT YOU WISH TO HAVE YOUR SHARES VOTED FOR THE MERGER
AGREEMENT AND THE MERGER. YOU MAY REVOKE YOUR PROXY BY SIGNING AND RETURNING A
LATER DATED PROXY WITH RESPECT TO THE SAME SHARES, BY FILING WITH THE SECRETARY
OF PLAINS A DULY EXECUTED REVOCATION, OR BY ATTENDING THE SPECIAL MEETING AND
VOTING IN PERSON (ALTHOUGH ATTENDANCE AT THE SPECIAL MEETING WILL NOT IN AND OF
ITSELF CONSTITUTE A REVOCATION OF YOUR PROXY).
 
                                          By order of the Board of Directors,
 
                                          Eugene A. Lang, Jr.
                                          Secretary
 
Lakewood, Colorado
June 13, 1995
<PAGE>

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A         +
+REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE   +
+SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR MAY  +
+OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT        +
+BECOMES EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR   +
+THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE      +
+SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE    +
+UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS OF  +
+ANY SUCH STATE.                                                               +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                   SUBJECT TO COMPLETION, DATED JUNE 9, 1995
 
      PRELIMINARY PROXY MATERIAL--NO PROXIES ARE BEING SOLICITED HEREWITH
 
                         BARRETT RESOURCES CORPORATION
                                      AND
                            PLAINS PETROLEUM COMPANY
 
                             JOINT PROXY STATEMENT
 
                                  -----------
 
                         BARRETT RESOURCES CORPORATION
                                   PROSPECTUS
 
                                  -----------
 
              SPECIAL MEETING OF STOCKHOLDERS OF BARRETT RESOURCES
                    CORPORATION TO BE HELD ON JULY 18, 1995
 
              SPECIAL MEETING OF STOCKHOLDERS OF PLAINS PETROLEUM
                      COMPANY TO BE HELD ON JULY 18, 1995
 
  This Joint Proxy Statement/Prospectus ("Joint Proxy Statement/Prospectus") is
being furnished to stockholders of Barrett Resources Corporation, a Delaware
corporation ("Barrett"), and to stockholders of Plains Petroleum Company, a
Delaware corporation ("Plains"), in connection with the solicitation of proxies
by the Board of Directors of each corporation for use at the Special Meeting of
Stockholders of Barrett (the "Barrett Special Meeting") and the Special Meeting
of Stockholders of Plains (the "Plains Special Meeting" and, together with the
Barrett Special Meeting, the "Special Meetings"), respectively, in each case
including any adjournments or postponements thereof. The Special Meetings are
both scheduled to be held on Tuesday, July 18, 1995. This Joint Proxy
Statement/Prospectus relates to the proposed merger (the "Merger") of Barrett
Energy Inc., a Delaware corporation and a wholly owned subsidiary of Barrett
("Sub"), with and into Plains pursuant to the Agreement and Plan of Merger,
dated as of May 2, 1995 (the "Merger Agreement"), among Barrett, Sub and
Plains, with Plains, as the surviving corporation in the Merger, to become a
wholly owned subsidiary of Barrett.
 
  Subject to certain provisions described herein with respect to shares owned
by Plains, Barrett and their respective subsidiaries, each outstanding share of
Common Stock, par value $.01 per share, of Plains (the "Plains Common Stock"),
together with its associated Preferred Stock Purchase Right (collectively, the
"Rights"), will be converted in the Merger into 1.3 validly issued, fully paid
and nonassessable shares of Common Stock, par value $.01 per share, of Barrett
(the "Barrett Common Stock"). Cash will be issued in lieu of fractional shares
of Barrett Common Stock.
 
  This Joint Proxy Statement/Prospectus constitutes a prospectus of Barrett
with respect to up to     shares of Barrett Common Stock issuable to Plains
stockholders in the Merger pursuant to the Merger Agreement or upon exercise of
certain stock options of Plains which, pursuant to the Merger Agreement and the
terms of the related stock option plans, following the Merger, will constitute
options to purchase shares of Barrett Common Stock upon the terms set forth in
such stock option plans and the Merger Agreement.
 
  The Barrett Common Stock is listed for trading on the New York Stock
Exchange, Inc. (the "NYSE") under the symbol "BRR" and the Plains Common Stock
is listed for trading on the NYSE under the symbol "PLP." On June 12, 1995, the
last sale prices of the Barrett Common Stock and the Plains Common Stock as
reported on the NYSE Composite Transactions Tape were $   per share and $   per
share, respectively. For a description of the Barrett Common Stock, see
"DESCRIPTION OF BARRETT COMMON STOCK" and "COMPARISON OF RIGHTS OF HOLDERS OF
PLAINS COMMON STOCK AND BARRETT COMMON STOCK."
 
  This Joint Proxy Statement/Prospectus, the accompanying forms of proxy and
the other enclosed documents are first being mailed to stockholders of Barrett
and Plains on or about June 15, 1995.
 
                                  -----------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS JOINT PROXY STATEMENT/PROSPECTUS. ANY
REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
 
                                  -----------
 
      The date of this Joint Proxy Statement/Prospectus is        , 1995.
<PAGE>
 
                [Principal Areas of Activity Map appears here]

                                       2
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
Available Information.....................................................   4
Incorporation of Certain Documents by
 Reference................................................................   4
Summary...................................................................   6
 The Companies............................................................   6
 Post-Merger Profile and Strategy.........................................   7
 The Special Meetings.....................................................   8
 The Merger...............................................................   9
 Selected Consolidated Financial Data of Barrett Resources Corporation....  14
 Selected Consolidated Financial Data of Plains Petroleum Company.........  15
 Selected Pro Forma Consolidated Financial Data...........................  16
 Comparative Per Common Share Data of Barrett Resources Corporation and
  Plains Petroleum Company................................................  18
 Comparative Stock Prices and Dividends...................................  19
Introduction..............................................................  20
Barrett Resources Corporation.............................................  20
 General..................................................................  20
 Piceance Basin Project...................................................  20
 Wind River Basin.........................................................  22
 Wyoming Overthrust.......................................................  23
 Greater Green River Basin................................................  23
 Oklahoma Project.........................................................  23
 Production...............................................................  25
 Productive Wells And Acreage.............................................  25
 Drilling Activity........................................................  26
 Reserves.................................................................  26
 Undeveloped Acreage......................................................  26
 Gas Marketing and Trading................................................  27
Plains Petroleum Company..................................................  27
 Southwest Kansas, Oklahoma and Northeast Colorado........................  28
 Gulf of Mexico...........................................................  29
 Permian Basin............................................................  29
 Wyoming and the Rocky Mountains..........................................  30
 Productive Wells.........................................................  32
 Drilling Activity........................................................  32
 Reserves.................................................................  32
 Production, Sales Prices And Production Costs............................  33
 Leased Acreage...........................................................  33
 Net Profit Agreements....................................................  34
 Hugoton Gas Trust Agreement..............................................  34
Post-Merger Profile and Strategy..........................................  34
 Oil and Gas Interests....................................................  34
 Strategy.................................................................  34
 Management...............................................................  35
The Special Meetings......................................................  38
 Matters To Be Considered at the Special
  Meetings................................................................  38
 Votes Required...........................................................  38
 Voting of Proxies........................................................  39
 Revocability of Proxies..................................................  39
 Record Dates; Stock Entitled To Vote;
  Quorum..................................................................   40
 Appraisal Rights.........................................................   40
 Solicitation of Proxies..................................................   41
The Merger................................................................   41
 General..................................................................   41
 Background of the Merger.................................................   41
 Recommendations of the Boards of Directors; Reasons for the Merger.......   48
 Opinions of Financial Advisors...........................................   52
 Merger Consideration.....................................................   62
 Effective Time of the Merger.............................................   62
 Conversions of Shares; Procedures for Exchange of Certificates...........   62
 Fractional Shares........................................................   63
 Conduct of Business Pending Merger.......................................   64
 Conditions to the Consummation of the
  Merger..................................................................   64
 Governmental and Regulatory Approvals....................................   64
 Certain Federal Income Tax Consequences..................................   65
 Anticipated Accounting Treatment.........................................   67
 Treatment of Plains Stock Options........................................   67
 Employee Benefits Matters................................................   67
 Interests of Certain Persons in the Merger...............................   68
 Stock Exchange Listing...................................................   69
 Resale of Barrett Common Stock...........................................   69
Unaudited Pro Forma Consolidated Condensed Financial Statements...........   69
Security Ownership of Management and Certain Beneficial Owners............   77
Description of Capital Stock of Barrett...................................   79
Description of Capital Stock of Plains....................................   80
Comparison of Rights of Holders of Plains
 Common Stock and Barrett Common Stock....................................   82
Certain Provisions of the Merger Agreement................................   88
Certain Litigation........................................................   96
Experts...................................................................   97
Legal Opinions............................................................   97
Other Information and Stockholder Proposals...............................   98
Barrett Management's Discussion and Analysis of Financial Condition and
 Results of Operations....................................................   99
Plains Management's Discussion and Analysis of Financial Condition and
 Results of Operations....................................................  104
Index to Consolidated Financial Statements of Barrett.....................  F-1
Index to Consolidated Financial Statements of Plains...................... F-30
Annexes
Annex I--Agreement and Plan of Merger
Annex II--Opinion of Petrie Parkman & Co.
Annex III--Opinion of Goldman, Sachs & Co.
Annex IV--Glossary
</TABLE>
 
                                       3
<PAGE>
 
  NO PERSONS HAVE BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATION OTHER THAN THOSE CONTAINED OR INCORPORATED BY REFERENCE IN THIS
JOINT PROXY STATEMENT/PROSPECTUS IN CONNECTION WITH THE OFFERING OF SECURITIES
MADE HEREBY AND, IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATION MUST NOT
BE RELIED UPON AS HAVING BEEN AUTHORIZED BY BARRETT OR PLAINS. THIS JOINT PROXY
STATEMENT/PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL, OR A SOLICITATION OF
AN OFFER TO BUY, ANY SECURITIES, NOR DOES IT CONSTITUTE THE SOLICITATION OF A
PROXY, IN ANY JURISDICTION TO OR FROM ANY PERSON TO WHOM IT IS NOT LAWFUL TO
MAKE ANY SUCH OFFER OR SOLICITATION IN SUCH JURISDICTION. NEITHER THE DELIVERY
OF THIS JOINT PROXY STATEMENT/PROSPECTUS NOR ANY DISTRIBUTION OF SECURITIES
MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE AN IMPLICATION THAT THERE
HAS BEEN NO CHANGE IN THE AFFAIRS OF BARRETT OR PLAINS SINCE THE DATE HEREOF OR
THAT THE INFORMATION HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO ITS DATE.
 
                             AVAILABLE INFORMATION
 
  Barrett and Plains are subject to the informational requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and in
accordance therewith file reports, proxy statements and other information with
the Securities and Exchange Commission (the "Commission"). The reports, proxy
statements and other information filed by Barrett and Plains with the
Commission can be inspected and copied at the public reference facilities
maintained by the Commission at Room 1024, 450 Fifth Street, N.W., Washington,
D.C. 20549, and should be available at the Commission's Regional Offices at 7
World Trade Center, 13th Floor, New York, New York 10048, and 500 West Madison
Street, Suite 1400, Chicago, Illinois 60661. Copies of such material also can
be obtained from the Public Reference Section of the Commission at 450 Fifth
Street, N.W., Washington, D.C. 20549, at prescribed rates. In addition,
material filed by Barrett and Plains can be inspected at the offices of the
NYSE, 20 Broad Street, New York, New York 10005.
 
  Barrett has filed with the Commission a Registration Statement on Form S-4
(together with any amendments thereto, the "Registration Statement") under the
Securities Act of 1933, as amended (the "Securities Act"), with respect to the
Barrett Common Stock to be issued in the Merger or upon exercise of stock
options of Plains which, following the Merger, will constitute options to
purchase shares of Barrett Common Stock upon the terms set forth in the related
stock option plans and the Merger Agreement. This Joint Proxy
Statement/Prospectus does not contain all the information set forth in the
Registration Statement and the exhibits thereto. Such additional information
may be obtained from the Commission's principal office in Washington, D.C.
Statements contained in this Joint Proxy Statement/Prospectus or in any
document incorporated in this Joint Proxy Statement/Prospectus by reference as
to the contents of any contract or other document referred to herein or therein
are not necessarily complete, and in each instance reference is made to the
copy of such contract or other document filed as an exhibit to the Registration
Statement or such other document, each such statement being qualified in all
respects by such reference.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
  The following documents filed with the Commission by Barrett (File No. 1-
13446) and Plains (File No. 1-8975) pursuant to the Exchange Act are
incorporated by reference in this Joint Proxy Statement/Prospectus:
 
    1. Barrett's Annual Report on Form 10-K for the fiscal year ended
  September 30, 1994;
 
    2. Barrett's Quarterly Report on Form 10-Q for the three months ended
  December 31, 1994;
 
    3. Barrett's Quarterly Report on Form 10-Q for the three months ended
  March 31, 1995;
 
    4. Barrett's Current Report on Form 8-K reporting an event occurring on
  May 2, 1995;
 
                                       4
<PAGE>
 
    5. The description of the Barrett Common Stock contained in Barrett's
  Registration Statement on Form 8-A filed with the Commission on October 27,
  1994;
 
    6. Plains' Annual Report on Form 10-K for the year ended December 31,
  1994;
 
    7. Plains' Quarterly Report on Form 10-Q for the three months ended March
  31, 1995;
 
    8. Plains' Amendment No. 1, dated January 12, 1995, to Plains' Current
  Report on Form 8-K reporting an event occurring on November 1, 1994 and
  Plains' Current Report on Form 8-K reporting an event occurring on May 2,
  1995;
 
    9. The description of the Plains Common Stock contained in Plains'
  Registration Statement on Form 10 filed with the Commission on August 21,
  1985; and
 
    10. The description of Plains' Rights Agreement contained in Plains'
  Registration Statement on Form 8-A dated May 20, 1988, as amended by the
  Form 8-A/A dated October 26, 1994.
 
  All documents and reports filed by Barrett or Plains pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this Joint
Proxy Statement/Prospectus and prior to the date of the respective Special
Meeting shall be deemed to be incorporated by reference in this Joint Proxy
Statement/Prospectus and to be a part hereof from the dates of filing of such
documents or reports. Any statement contained in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Joint Proxy Statement/Prospectus to the extent
that a statement contained herein or in any other subsequently filed document
which also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of
this Joint Proxy Statement/Prospectus.
 
  THIS JOINT PROXY STATEMENT/PROSPECTUS INCORPORATES DOCUMENTS BY REFERENCE
WHICH ARE NOT PRESENTED HEREIN OR DELIVERED HEREWITH. SUCH DOCUMENTS (OTHER
THAN EXHIBITS TO SUCH DOCUMENTS UNLESS SUCH EXHIBITS ARE SPECIFICALLY
INCORPORATED BY REFERENCE) ARE AVAILABLE, WITHOUT CHARGE, TO ANY PERSON,
INCLUDING ANY BENEFICIAL OWNER, TO WHOM THIS JOINT PROXY STATEMENT/PROSPECTUS
IS DELIVERED, ON WRITTEN OR ORAL REQUEST, WITHIN ONE BUSINESS DAY OF SUCH
REQUEST, IN THE CASE OF DOCUMENTS RELATING TO BARRETT, TO BARRETT RESOURCES
CORPORATION, 1125 SEVENTEENTH STREET, SUITE 2400, DENVER, COLORADO 80202
(TELEPHONE NUMBER: 303-297-3900), ATTENTION: DONALD H. STEVENS, VICE PRESIDENT;
OR, IN THE CASE OF DOCUMENTS RELATING TO PLAINS, TO PLAINS PETROLEUM COMPANY,
12596 WEST BAYAUD AVENUE, SUITE 400, LAKEWOOD, COLORADO 80228 (TELEPHONE NUMBER:
303-969-9325), ATTENTION: EUGENE A. LANG, JR., SECRETARY. IN ORDER TO ENSURE
DELIVERY OF THE DOCUMENTS PRIOR TO THE APPLICABLE SPECIAL MEETING, REQUESTS
SHOULD BE RECEIVED BY JULY 11, 1995.
 
  All information contained or incorporated by reference in this Joint Proxy
Statement/Prospectus relating to Barrett or Sub has been supplied by Barrett,
and all such information relating to Plains has been supplied by Plains.
 
                                       5
<PAGE>
 
                                    SUMMARY
 
  The following is a summary of certain information contained elsewhere or
incorporated by reference in this Joint Proxy Statement/Prospectus. Reference
is made to, and this summary is qualified in its entirety by, the more detailed
information contained or incorporated by reference in this Joint Proxy
Statement/Prospectus and the Annexes hereto. As used herein, unless the context
otherwise requires, "Barrett" means Barrett Resources Corporation and its
consolidated subsidiaries, and "Plains" means Plains Petroleum Company and its
consolidated subsidiaries. "Sub" means Barrett Energy Inc., a wholly owned
subsidiary of Barrett. Certain oil and gas terms used herein are defined in the
Glossary, which appears as Annex IV hereto.
 
                                ----------------
 
  STOCKHOLDERS OF BARRETT AND PLAINS ARE URGED TO READ THIS JOINT PROXY
STATEMENT/PROSPECTUS AND THE ANNEXES HERETO IN THEIR ENTIRETY. STOCKHOLDERS
SHOULD CAREFULLY CONSIDER THE INFORMATION SET FORTH BELOW UNDER THE HEADING
"OTHER SIGNIFICANT CONSIDERATIONS."
 
                                ----------------
 
THE COMPANIES
 
  BARRETT RESOURCES CORPORATION AND SUB. Barrett is an independent oil and gas
exploration and production company with major emphasis in the Rocky Mountain
region and Oklahoma. Barrett principally utilizes its own exploration staff to
develop a geologic concept into an exploration prospect. After the prospect is
generated, Barrett's land department attempts to acquire a large lease block in
the area of the prospect. Barrett's strategy is to develop prospects and to
acquire acreage in identified core areas of interest.
 
  As of March 31, 1995, Barrett had interests in 468 producing natural gas
wells and 76 producing oil wells located on approximately 128,431 gross (33,163
net) developed acres with estimated proved reserves of 226 Bcf of natural gas
and 0.9 million barrels of oil. During the fiscal year of Barrett ended
September 30, 1994, natural gas accounted for more than 96% of Barrett's total
production. Its reserves are located in the lower 48 states, principally in the
Piceance Basin of Colorado, the Wind River Basin of Wyoming, and the Arkoma and
Anadarko Basins of Oklahoma. Also as of March 31, 1995, Barrett had interests
in 140,608 gross (66,431 net) undeveloped leasehold acres.
 
  Barrett will act as the operator of its exploration or development drilling
programs whenever possible. As of March 31, 1995, Barrett was serving as
operator for approximately 245 producing wells, 32 shut-in wells, three wells
that were drilling, three wells that were being completed and 10 wells that
were waiting on completion.
 
  Barrett is a Delaware corporation with executive offices located at 1125
Seventeenth Street, Suite 2400, Denver, Colorado 80202, and its telephone
number at that address is (303) 297-3900.
 
  Sub was organized as a Delaware corporation in 1995 for the purpose of
consummating the Merger and the other transactions contemplated by the Merger
Agreement. Sub has no assets or business and has not carried on any activities
to date other than incident to its formation and in connection with the Merger
and the other transactions contemplated by the Merger Agreement. Sub's offices
are located at 1125 Seventeenth Street, Suite 2400, Denver, Colorado 80202, and
its telephone number at that address is (303) 297-3900.
 
  PLAINS PETROLEUM COMPANY. Plains is an independent oil and gas exploration
and production company with interests in 653 producing natural gas wells and
853 producing oil wells located on approximately 344,455 gross (240,548 net)
acres held by production with estimated proved reserves of 312.5 Bcf of natural
gas and 11 million barrels of oil at December 31, 1994. The reserves are
located in the lower 48 states,
 
                                       6
<PAGE>
 
principally in the Kansas and Oklahoma portions of the Hugoton Field, in the
Permian Basin of west Texas and southeast New Mexico, in the Powder River and
Green River Basins of Wyoming, and in Louisiana state waters. In 1994,
approximately 47% of Plains' natural gas revenues (approximately 34% of total
revenues) came from sales made to K N Energy, Inc. ("K N"), its principal
purchaser, under a long-term natural gas purchase contract.
 
  Plains was incorporated as a wholly owned subsidiary of K N in 1983. Plains
was formed to own and operate substantially all of K N's natural gas and oil
producing properties. On September 13, 1985, K N distributed the shares of
Plains Common Stock held by it to the K N shareholders, which resulted in K N
no longer holding an ownership position in Plains and in the trading of the
Plains Common Stock on the NYSE as a separate and distinct public entity.
 
  Plains is a Delaware corporation with executive offices located at 12596 West
Bayaud Avenue, Lakewood, Colorado 80228, and its telephone number at that
address is (303) 969-9325.
 
POST-MERGER PROFILE AND STRATEGY
 
  OIL AND GAS INTERESTS. As a result of the Merger, Barrett will have interests
in the Rocky Mountain, Mid-Continent and Gulf Coast areas, including the
Piceance, Wind River, Powder River, Green River, Arkoma, Anadarko, Permian,
Gulf Coast and Washakie-Red Desert Basins. Also following the Merger, Barrett
will have interests in an aggregate of 470,886 gross (273,211 net) developed
acres and 440,020 gross (166,408 net) undeveloped acres.
 
  Based on the March 31, 1995 estimated proved reserves of Barrett and the
December 31, 1994 estimated proved reserves of Plains, Barrett will have
estimated proved reserves after the Merger of 609.7 Bcfe (approximately 85% of
which will be natural gas). During the quarter ended March 31, 1995, the daily
average production of Barrett and Plains on a combined basis was 158.1 MMcfe.
As of March 31, 1995, after giving effect to the Merger, Barrett and Plains had
interests in an aggregate of 2,092 producing natural gas and oil wells.
 
  STRATEGY. After the Merger, Barrett intends to continue its strategy of
aggressive growth in reserves and production primarily through generating its
own exploration and development drilling projects. By utilizing the larger cash
flow and other financial resources of the combined entity, Barrett anticipates
that it will be able to develop and exploit more aggressively its and Plains'
existing and future exploration and development projects.
 
  Because of the greater financial strength and size of the combined entity,
Barrett believes that it will be able to operate and compete more effectively
and to take advantage of opportunities in its current and post-Merger areas of
operations. As a result of having production and reserves in a larger number of
areas, it is anticipated that the combined entity also will be exposed to a
greater number of opportunities to expand its reserve base.
 
  Barrett anticipates that the combined entity will be able to realize
significant reductions in general and administrative expenses from the pre-
Merger combined expenses of Barrett and Plains. It is expected that the
majority of these cost reductions will be through elimination of duplicative
personnel, accounting and other systems, and certain other administrative and
fixed costs of the two pre-Merger companies.
 
  Barrett currently has a line of credit which provides for borrowings up to
$80 million and a borrowing base of $40 million. Plains currently has a $150
million line of credit with an initial borrowing base of $110
 
                                       7
<PAGE>
 
million, which the lender can accelerate and terminate upon a change of control
of Plains, such as upon consummation of the Merger. In connection with the
Merger, Barrett anticipates entering into a single new credit facility. Barrett
has had preliminary discussions with lenders that participate in one or both of
the pre-Merger companies' lines of credit, although no financing commitments
have been requested or made.
 
  MANAGEMENT. At the effective time of the Merger (the "Effective Time"),
Barrett's Board of Directors will be increased from nine to 13 members, and the
directors of Barrett will elect four new directors that have been designated by
Plains (the "Plains Designees") to fill the newly created vacancies. Plains has
informed Barrett that Derrill Cody, William W. Grant, III, William F. Wallace
and Harry S. Welch will be the Plains Designees. All of the Plains Designees
currently are directors of Plains. The terms of all directors of Barrett,
including the Plains Designees, will expire at the next annual meeting of
stockholders of Barrett.
 
  In addition, following the Effective Time, William J. Barrett will continue
as Chairman and Chief Executive Officer of Barrett, Paul M. Rady will continue
as President and Chief Operating Officer of Barrett, and William F. Wallace,
currently the President and Chief Operating Officer of Plains, will become Vice
Chairman of Barrett. See "POST-MERGER PROFILE AND STRATEGY--Management."
 
THE SPECIAL MEETINGS
 
 TIME AND PLACE
 
  The Barrett Special Meeting will be held at 11:00 a.m., Denver time, on
Tuesday, July 18, 1995, at the Brown Palace Hotel, 321 Seventeenth Street,
Denver, Colorado. The Plains Special Meeting will be held at 9:00 a.m., Denver
time, on Tuesday, July 18, 1995, at the Brown Palace Hotel, 321 Seventeenth
Street, Denver, Colorado.
 
 MATTERS TO BE CONSIDERED AT THE SPECIAL MEETINGS
 
  BARRETT SPECIAL MEETING. At the Barrett Special Meeting, holders of shares of
Barrett Common Stock will consider and vote upon proposals to (i) approve an
amendment to Barrett's Certificate of Incorporation to increase the number of
authorized shares of Barrett Common Stock from 17,000,000 shares to 35,000,000
shares (the "Charter Amendment") and (ii) approve the issuance of shares of
Barrett Common Stock (the "Stock Issuance") in connection with the Merger
Agreement, a conformed copy of which appears as Annex I to this Joint Proxy
Statement/Prospectus, including the issuance of shares of Barrett Common Stock
in the Merger and the reservation of shares of Barrett Common Stock for
issuance upon exercise of stock options of Plains which, following the Merger,
will constitute options to purchase Barrett Common Stock upon the terms set
forth in the related stock option plans and the Merger Agreement. Holders of
shares of Barrett Common Stock entitled to vote also will consider and vote
upon any other matter that may properly come before the Barrett Special Meeting
or any adjournments or postponements thereof.
 
  PLAINS SPECIAL MEETING. At the Plains Special Meeting, holders of shares of
Plains Common Stock will consider and vote upon a proposal to approve and adopt
the Merger Agreement, which provides for the Merger of Sub with and into
Plains, with Plains to be the surviving corporation in the Merger and a wholly
owned subsidiary of Barrett. Holders of shares of Plains Common Stock entitled
to vote also will consider and vote upon any other matter that may properly
come before the Plains Special Meeting or any adjournments or postponements
thereof.
 
 VOTES REQUIRED
 
  BARRETT. The approval of the Charter Amendment requires the affirmative vote
of a majority of the outstanding shares of Barrett Common Stock. The approval
of the Stock Issuance requires the affirmative vote of a majority of the votes
cast on the proposal, provided that the total votes cast on the proposal
represent a majority of the outstanding shares of Barrett Common Stock entitled
to vote thereon.
 
                                       8
<PAGE>
 
 
  Abstentions will have the effect of votes against approval of the Charter
Amendment and the Stock Issuance. In addition, brokers who hold shares of
Barrett Common Stock as nominees will not have discretionary authority to vote
such shares in the absence of instructions from the beneficial owners thereof.
Votes which are not cast for this reason ("broker non-votes") also will have
the effect of a vote against the Charter Amendment. Broker non-votes with
respect to the Stock Issuance will not have the effect of a vote for or against
the matter. See "THE SPECIAL MEETINGS--Votes Required--Barrett."
 
  PLAINS. The adoption and approval of the Merger Agreement requires the
affirmative vote of a majority of the outstanding shares of Plains Common Stock
entitled to vote thereon.
 
  Abstentions will have the effect of votes against approval and adoption of
the Merger Agreement, the Merger and the other transactions contemplated by the
Merger Agreement. In addition, brokers who hold shares of Plains Common Stock
as nominees will not have discretionary authority to vote such shares in the
absence of instructions from the beneficial owners thereof. Broker non-votes
will have the effect of a vote against the proposal. See "THE SPECIAL
MEETINGS--Votes Required--Plains."
 
  RECORD DATES. The record date for the determination of holders of Barrett
Common Stock and Plains Common Stock entitled to notice of and to vote at the
Special Meetings is June 13, 1995. On that date, Barrett had outstanding
shares of Barrett Common Stock, and Plains had outstanding     shares of Plains
Common Stock.
 
  SECURITY OWNERSHIP OF MANAGEMENT. As of June 13, 1995, directors and
executive officers of Barrett and their affiliates were beneficial owners of an
aggregate of 2,137,193 shares (approximately 17.7%) of the outstanding shares
of Barrett Common Stock (including 132,297 shares subject to options
exercisable within 60 days). As of June 13, 1995, directors and executive
officers of Plains and their affiliates were beneficial owners of an aggregate
of 268,267 shares (approximately 2.7%) of the outstanding shares of Plains
Common Stock (including 219,073 shares subject to options exercisable within 60
days).
 
  The directors of Barrett who are also stockholders of Barrett have committed
to vote their shares of Barrett Common Stock in favor of the matters submitted
to stockholders of Barrett at the Barrett Special Meeting. The directors of
Plains who are also stockholders of Plains have committed to vote their shares
of Plains Common Stock in favor of the matters submitted to stockholders of
Plains at the Plains Special Meeting. As of June 13, 1995, the directors of
Barrett beneficially owned 1,983,183 shares of Barrett Common Stock (excluding
shares subject to options) and the directors of Plains beneficially owned
22,774 shares of Plains Common Stock (excluding shares subject to options).
 
THE MERGER
 
  EFFECT OF MERGER. At the Effective Time, Sub will be merged with and into
Plains, which will be the surviving corporation in the Merger (the "Surviving
Corporation"). As a result of the Merger, Plains will become a wholly owned
subsidiary of Barrett. Subject to certain provisions described herein with
respect to shares owned by Barrett, Plains, Sub and the respective subsidiaries
of Barrett and Plains, each issued and outstanding share of Plains Common Stock
together with its associated Right issued pursuant to the Rights Agreement,
dated as of May 12, 1988, as amended (the "Rights Agreement"), between Plains
and Chemical Bank (successor to Manufacturers Hanover Trust Company), as Rights
Agent, will be converted in the Merger into 1.3 (the "Exchange Ratio") validly
issued, fully paid and nonassessable shares of Barrett Common Stock. Cash will
be paid in lieu of fractional shares of Barrett Common Stock. See "THE MERGER--
Fractional Shares."
 
  RECOMMENDATIONS OF THE BOARDS OF DIRECTORS. The respective Boards of
Directors of Barrett and Plains believe that the terms of the Merger are fair
to and advisable and in the best interests of their respective stockholders and
have unanimously approved the Merger Agreement, the Merger and the other
related transactions.
 
                                       9
<PAGE>
 
 
  THE BOARD OF DIRECTORS OF BARRETT UNANIMOUSLY RECOMMENDS THAT THE HOLDERS OF
BARRETT COMMON STOCK APPROVE THE CHARTER AMENDMENT AND THE STOCK ISSUANCE.
 
  THE BOARD OF DIRECTORS OF PLAINS UNANIMOUSLY RECOMMENDS THAT THE HOLDERS OF
PLAINS COMMON STOCK APPROVE AND ADOPT THE MERGER AGREEMENT AND THE MERGER.
 
  For additional information with respect to the determinations made by and the
recommendations of the Barrett and Plains Boards of Directors, see "THE
MERGER--Recommendations of the Boards of Directors; Reasons for the Merger."
 
  OPINIONS OF FINANCIAL ADVISORS. Petrie Parkman & Co. Inc. ("Petrie Parkman")
delivered its written opinion dated May 2, 1995 to the Barrett Board of
Directors that, as of May 2, 1995, the Exchange Ratio pursuant to the Merger
Agreement is fair, from a financial point of view, to the holders of Barrett
Common Stock. Petrie Parkman subsequently delivered its written opinion, dated
the date hereof, to the Barrett Board of Directors that as of the date hereof
the Exchange Ratio pursuant to the Merger Agreement is fair, from a financial
point of view, to the holders of Barrett Common Stock.
 
  The full text of the written opinion of Petrie Parkman, dated the date
hereof, which sets forth assumptions made, matters considered and limitations
on the review undertaken in connection with the opinion, is attached hereto as
Annex II and is incorporated herein by reference. Holders of Barrett Common
Stock are urged to, and should, read this opinion in its entirety. See "THE
MERGER--Opinions of Financial Advisors--Petrie Parkman Opinion to the Barrett
Board of Directors."
 
  Goldman, Sachs & Co. ("Goldman Sachs") delivered their written opinion dated
May 2, 1995 to the Plains Board of Directors that, as of May 2, 1995, the
Exchange Ratio pursuant to the Merger Agreement is fair to the holders of
Plains Common Stock. Goldman Sachs subsequently delivered their written
opinion, dated the date hereof, to the Plains Board of Directors that as of the
date hereof the Exchange Ratio pursuant to the Merger Agreement is fair to the
holders of Plains Common Stock.
 
  The full text of the written opinion of Goldman Sachs, dated the date hereof,
which sets forth assumptions made, matters considered and limitations on the
review undertaken in connection with the opinion, is attached hereto as Annex
III and is incorporated herein by reference. Holders of Plains Common Stock are
urged to, and should, read this opinion in its entirety. See "THE MERGER--
Opinions of Financial Advisors--Goldman Sachs Opinion to the Plains Board of
Directors."
 
  EFFECTIVE TIME OF THE MERGER. The Merger will become effective upon the
filing and acceptance of the Certificate of Merger with the Secretary of State
of the State of Delaware or such later date as is specified in such
Certificate. The filing of the Certificate of Merger will occur as soon as
practicable following the satisfaction or waiver of the conditions set forth in
the Merger Agreement. See "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--
Conditions to the Merger."
 
  INTERESTS OF CERTAIN PERSONS IN THE MERGER. Shares of Plains Common Stock
held by executive officers and directors of Plains will be converted in the
same manner and on the same basis as shares of Plains Common Stock held by
other stockholders. At the Effective Time, outstanding options to purchase
shares of Plains Common Stock ("Plains Stock Options") will become and
represent options to acquire a number of shares of Barrett Common Stock equal
to the number of shares of Plains Common Stock subject to such Plains Stock
Options times the Exchange Ratio at an exercise price per share of Barrett
Common Stock equal to the exercise price per share of Plains Common Stock
immediately prior to the Effective Time divided by the Exchange Ratio.
 
  At the Effective Time, Barrett's Board of Directors will be increased from
nine to 13 members, and the directors of Barrett will elect the Plains
Designees to fill the newly created vacancies. The terms of all
 
                                       10
<PAGE>
 
directors of Barrett, including the Plains Designees, will expire at the next
annual meeting of stockholders of Barrett. Also at the Effective Time, William
J. Barrett will continue as Chairman and Chief Executive Officer of Barrett,
Paul M. Rady will continue as President and Chief Operating Officer of Barrett,
and William F. Wallace, currently the President and Chief Operating Officer of
Plains, will become Vice Chairman of Barrett.
 
  In addition, the Merger Agreement provides for certain directors, officers
and other employees of Plains to continue to receive or be eligible for certain
benefits and other matters following the Effective Time. See "POST-MERGER
PROFILE AND STRATEGY--Management," "THE MERGER--Interests of Certain Persons in
the Merger" and "--Treatment of Plains Stock Options" and "CERTAIN PROVISIONS
OF THE MERGER AGREEMENT."
 
  CONDITIONS TO THE MERGER. The obligations of Barrett, Sub and Plains to
consummate the Merger are subject to various conditions, including, among other
things, obtaining the requisite stockholder approvals, the authorization for
listing on the NYSE of the shares of Barrett Common Stock issuable to Plains
stockholders pursuant to the Merger Agreement, the expiration or termination of
the applicable waiting period under the Hart-Scott-Rodino Antitrust
Improvements Act of 1976, as amended (the "HSR Act"), the effectiveness of the
Registration Statement and the absence of any order or other legal restraint or
prohibition preventing the consummation of the Merger. The obligation of
Barrett to consummate the Merger is subject to the fulfillment or waiver of
various additional conditions, including, among other things, that, based on
the advice of its independent accountants and such other advice as Barrett
deems relevant, Barrett shall have no reasonable basis for believing that
following the Merger the combination of Plains and Sub may not be accounted for
as a "pooling of interests" in accordance with generally accepted accounting
principles. The obligation of Plains to consummate the Merger is subject to the
fulfillment or waiver of various additional conditions, including, among other
things, that Barrett's Board of Directors shall have taken all necessary and
appropriate actions to cause the number of directors comprising its Board of
Directors to be increased by four and the vacancies thus created to be filled
at the Effective Time by the election of the Plains Designees. See "POST-MERGER
PROFILE AND STRATEGY--Management," "THE MERGER--Conditions to the Consummation
of the Merger" and "--Governmental and Regulatory Approvals" and "CERTAIN
PROVISIONS OF THE MERGER AGREEMENT--Conditions to the Consummation of the
Merger."
 
  TERMINATION OF THE MERGER AGREEMENT. The Merger Agreement may be terminated
at any time prior to the Effective Time (i) by mutual consent of Barrett and
Plains, (ii) by either Barrett or Plains (a) if any court or other governmental
entity shall have issued a final and nonappealable order, decree or ruling or
taken any other final and nonappealable action permanently enjoining or
otherwise prohibiting the Merger, (b) if the Merger shall not have been
consummated on or before December 31, 1995 (other than due to the failure of
the party seeking to terminate the Merger Agreement to perform its obligations
under the Merger Agreement), or (c) if, under certain circumstances, the
required stockholder approvals are not obtained, and (iii) by Barrett or Plains
in certain other situations, including in the event of certain competing
transactions with respect to Plains or a withdrawal or modification by the
Plains Board of Directors of its recommendation of the Merger. See "CERTAIN
PROVISIONS OF THE MERGER AGREEMENT--Termination." The Merger Agreement provides
that in the event of a termination in certain situations in which there is a
competing transaction with respect to Plains, or in the event that Plains
enters into certain business combination transactions with another person
within nine months following termination under certain events, Barrett will
receive a termination fee of $8 million. In the event of a termination by
Barrett resulting from a modification or withdrawal by the Plains Board of
Directors of its recommendation of the Merger or its declaration that the
Merger is fair to and advisable and in the best interests of its stockholders,
or a resolution by the Plains Board of Directors to do so, Barrett will receive
a termination fee of $5 million and, in the event that Plains enters into
certain business combination transactions with another person within nine
months thereafter, Plains will pay an additional fee of $3 million. See
"CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Fees and Expenses."
 
                                       11
<PAGE>
 
 
  DISSENTING STOCKHOLDERS' RIGHTS OF APPRAISAL. In accordance with the General
Corporation Law of the State of Delaware (the "DGCL"), dissenting stockholders
of Plains and Barrett will not be entitled to appraisal rights in connection
with the Merger. See "THE SPECIAL MEETINGS--Appraisal Rights."
 
  CERTAIN FEDERAL INCOME TAX CONSEQUENCES.  For U.S. federal income tax
purposes, it is intended that the Merger qualify as a "reorganization" within
the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended
(the "Code"), no gain or loss will be recognized by Barrett, Plains or Sub as a
result of the Merger and no gain or loss will be recognized by stockholders of
Plains upon the conversion of their Plains Common Stock into shares of Barrett
Common Stock pursuant to the Merger except with respect to cash, if any,
received in lieu of fractional shares of Barrett Common Stock. Special rules
may apply to a stockholder of Plains who, for U.S. federal income tax purposes,
is a non-resident alien individual, a foreign corporation, a foreign
partnership or a foreign estate or trust. For a discussion of these and other
federal income tax considerations in connection with the Merger, see "THE
MERGER--Certain Federal Income Tax Consequences."
 
  EACH HOLDER OF PLAINS COMMON STOCK SHOULD CONSULT HIS OWN TAX ADVISOR
REGARDING THE TAX CONSEQUENCES OF THE MERGER IN LIGHT OF SUCH HOLDER'S OWN
SITUATION, INCLUDING THE APPLICATION AND EFFECT OF ANY STATE, LOCAL OR FOREIGN
INCOME AND OTHER TAX LAWS.
 
  ACCOUNTING TREATMENT OF THE MERGER. The Merger is expected to be accounted
for as a "pooling of interests" in accordance with generally accepted
accounting principles. Following the Merger, Barrett will continue to follow
the "full cost" method of accounting for its oil and natural gas exploration
and development activities and will change its fiscal year end to December 31
from September 30. Plains currently follows the "successful efforts" method of
accounting for such activities and has a December 31 fiscal year end. See "THE
MERGER--Anticipated Accounting Treatment" and "UNAUDITED PRO FORMA CONSOLIDATED
CONDENSED FINANCIAL STATEMENTS."
 
  COMPARISON OF RIGHTS OF HOLDERS OF PLAINS COMMON STOCK AND BARRETT COMMON
STOCK. See "COMPARISON OF RIGHTS OF HOLDERS OF PLAINS COMMON STOCK AND BARRETT
COMMON STOCK" for a summary of the material differences between the rights of
holders of Plains Common Stock and Barrett Common Stock.
 
  OTHER SIGNIFICANT CONSIDERATIONS. In determining whether to approve the
transactions pursuant to the Merger Agreement, Barrett and Plains stockholders
should consider that the price of the Barrett Common Stock at the Effective
Time, as well as the prices at the date of this Joint Proxy
Statement/Prospectus and at the date of the Special Meetings, may vary as a
result of changes in the business, operations or prospects of Barrett, market
assessments of the likelihood that the Merger will be consummated and the
timing thereof, general market and economic conditions and other factors.
Because the Effective Time may occur at a later date than the date of the
Special Meetings, there can be no assurance that the sales price of Barrett
Common Stock on the date of the Special Meetings will be indicative of the
sales price of Barrett Common Stock at the Effective Time. The Effective Time
will occur as soon as practicable following the Special Meetings and the
satisfaction or waiver of the other conditions set forth in the Merger
Agreement. See "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Conditions to the
Merger."
 
  Stockholders of Barrett and Plains should also consider that the Exchange
Ratio is a fixed ratio in the Merger Agreement. As a result, the Exchange Ratio
will not be adjusted in the event of an increase or decrease in the market
price of either the Barrett Common Stock or the Plains Common Stock, or both.
Barrett and Plains stockholders are urged to obtain current market quotations
for the Barrett Common Stock and the Plains Common Stock.
 
  Plains stockholders should also consider that the rights of holders of
Barrett Common Stock differ in a number of significant respects from the rights
of holders of Plains Common Stock. For a discussion of the rights of the
Barrett Common Stock, see "DESCRIPTION OF CAPITAL STOCK OF BARRETT" and
"COMPARISON OF RIGHTS OF HOLDERS OF PLAINS COMMON STOCK AND BARRETT COMMON
STOCK."
 
                                       12
<PAGE>
 
 
  Based on the number of shares outstanding on the Record Date, upon
consummation of the Merger, there will be approximately     shares of Barrett
Common Stock outstanding and the shares of Barrett Common Stock issued to
stockholders of Plains pursuant to the Merger Agreement will comprise
approximately  % of the total number of shares of Barrett Common Stock
outstanding (approximately  % on a fully diluted basis).
 
 
                                       13
<PAGE>
 
     SELECTED CONSOLIDATED FINANCIAL DATA OF BARRETT RESOURCES CORPORATION
 
  The following table sets forth selected consolidated historical financial
data of Barrett and has been derived from and should be read in conjunction
with the audited consolidated financial statements of Barrett for each of the
five fiscal years ended September 30, 1994 and the unaudited interim
consolidated financial statements of Barrett for the six months ended March 31,
1994 and March 31, 1995, including the respective notes thereto, included
herein. See "AVAILABLE INFORMATION" and "INCORPORATION OF CERTAIN DOCUMENTS BY
REFERENCE." In the opinion of management, all adjustments, consisting of normal
recurring accruals, considered necessary for a fair presentation have been
included in the unaudited interim data. Unaudited interim results are not
necessarily indicative of results which may be expected for future periods.
<TABLE>
<CAPTION>
                                                            AS OF AND FOR THE
                              AS OF AND FOR THE             SIX MONTHS ENDED
                           YEAR ENDED SEPTEMBER 30,             MARCH 31,
                   ---------------------------------------- -----------------
                    1990    1991    1992    1993     1994     1994     1995
                   ------- ------- ------- ------- -------- -------- --------
                    (IN THOUSANDS, EXCEPT PERCENTAGES AND PER SHARE AMOUNTS)
<S>                <C>     <C>     <C>     <C>     <C>      <C>      <C>     
REVENUES
  Oil and gas
   production....  $ 4,372 $ 5,207 $ 6,626 $14,976 $ 17,577 $  9,416 $ 10,343
  Trading
   revenues......       86   5,485  16,726  26,357   22,443    9,398   18,520
  Revenues from
   gas gathering.      358     498     279     271      252      137      442
  Interest
   income........    1,043   1,230     600     498      891      472      205
  Other income...       48      53      54     584       89       44       41
                   ------- ------- ------- ------- -------- -------- --------
                     5,907  12,473  24,285  42,686   41,252   19,467   29,551
OPERATING
 EXPENSES
  Lease operating
   expenses......      987   1,336   1,397   2,725    3,535    1,742    2,390
  Depreciation,
   depletion and
   amortization..    1,857   2,409   3,259   6,130    6,915    3,485    4,806
  Cost of
   trading.......       70   4,892  16,601  25,343   21,577    8,954   17,869
  General and
   administrative.   1,068   1,938   2,062   2,565    4,713    2,423    2,983
  Interest
   expense.......      138      40      26      13        6        4      370
                   ------- ------- ------- ------- -------- -------- --------
                     4,120  10,615  23,345  36,776   36,746   16,608   28,418
                   ------- ------- ------- ------- -------- -------- --------
EARNINGS BEFORE
 TAXES...........    1,787   1,858     940   5,910    4,506    2,859    1,133
                   ------- ------- ------- ------- -------- -------- --------
PROVISIONS FOR
 INCOME TAXES....      154     144      18     154       67       57       23
                   ------- ------- ------- ------- -------- -------- --------
NET EARNINGS
  Before
   accounting
   changes.......    1,633   1,714     922   5,756    4,439    2,802    1,110
  Accounting
   changes:
    Income taxes.      --      --      583     --       --       --       --
                   ------- ------- ------- ------- -------- -------- --------
                   $ 1,633 $ 1,714 $ 1,505 $ 5,756 $  4,439 $  2,802 $  1,110
                   ======= ======= ======= ======= ======== ======== ========
AVERAGE SHARES
 OUTSTANDING.....    7,892   9,901   9,733  10,908   11,917   11,910   12,106
                   ======= ======= ======= ======= ======== ======== ========
EARNINGS PER
 SHARE:
  Before
   accounting
   changes.......  $  0.21 $  0.17 $  0.09 $  0.53 $   0.37 $   0.23 $   0.09
  Accounting
   changes:
    Income taxes.      --      --     0.06     --       --       --       --
                   ------- ------- ------- ------- -------- -------- --------
  Net earnings...  $  0.21 $  0.17 $  0.15 $  0.53 $   0.37 $   0.23 $   0.09
                   ======= ======= ======= ======= ======== ======== ========
OPERATING DATA:
  EBITDA*........  $ 2,739 $ 3,077 $ 3,625 $11,555 $ 10,536 $  5,876 $  6,104
  Net cash flow
   provided by
   operations....    3,037   4,454   4,970   9,857   11,700    9,499    5,508
BALANCE SHEET
 DATA:
  Property and
   equipment,
   net...........  $22,438 $30,544 $36,360 $36,267 $ 76,925 $ 76,925 $ 98,360
  Total assets...   51,677  55,488  56,579  90,740  105,892  105,892  131,840
  Long-term debt,
   including
   current
   portion.......      473     583     --      --       --       --    31,000
  Stockholders'
   equity........   40,294  42,031  43,315  68,192   72,872   72,872   74,123
  Total debt-to-
   stockholders'
   equity ratio..       1%      1%      0%      0%       0%       0%      42%
</TABLE>
- --------
*  Reflects earnings before taxes less interest income, plus interest expense,
   plus depreciation, depletion and amortization expense. This data does not
   purport to reflect any measure of operations or cash flows.
 
                                       14
<PAGE>
 
                      SELECTED CONSOLIDATED FINANCIAL DATA
                          OF PLAINS PETROLEUM COMPANY
 
  The following table sets forth selected consolidated historical financial
data of Plains and has been derived from and should be read in conjunction with
the audited consolidated financial statements of Plains for each of the five
fiscal years ended December 31, 1994 and the unaudited interim consolidated
financial statements of Plains for the three months ended March 31, 1994 and
March 31, 1995, including the respective notes thereto, included herein. See
"AVAILABLE INFORMATION" and "INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE."
In the opinion of management, all adjustments, consisting of normal recurring
accruals, considered necessary for a fair presentation have been included in
the unaudited interim data. Unaudited interim results are not necessarily
indicative of results which may be expected for future periods.
<TABLE>
<CAPTION>
                                                                           AS OF AND FOR THE
                                       AS OF AND FOR THE                     THREE MONTHS
                                    YEAR ENDED DECEMBER 31,                 ENDED MARCH 31,
                          -----------------------------------------------  ------------------
                           1990      1991      1992      1993      1994      1994      1995
                          -------  --------  --------  --------  --------  --------  --------
                            (IN THOUSANDS, EXCEPT PERCENTAGES AND PER SHARE AMOUNTS)
<S>                       <C>      <C>       <C>       <C>       <C>       <C>       <C>
REVENUES
 Gas sales..............  $37,378  $ 41,512  $ 39,623  $ 46,189  $ 44,505  $ 12,783  $ 12,346
 Oil and condensate
  sales.................   11,413    17,194    18,918    18,091    17,188     3,393     6,288
                          -------  --------  --------  --------  --------  --------  --------
                           48,791    58,706    58,541    64,280    61,693    16,176    18,634
                          -------  --------  --------  --------  --------  --------  --------
OPERATING EXPENSES
 Production:
 Lease operations.......    6,106     8,575    11,503    12,537    10,810     2,720     3,519
 Production and property
  taxes.................    5,169     6,566     7,514     7,406     8,161     1,957     2,432
 Transportation and
  processing............      593     1,085     1,875     2,640     2,476       649       821
 Net profit payments....    4,837     5,474     4,575     4,748     3,247     1,288       668
 General and administra-
  tive..................    4,611     4,958     5,559     6,415     7,350     1,843     2,061
 Depreciation, depletion
  and amortization......    4,995     8,547    11,415    15,282    17,353     4,467     4,983
 Exploration............    3,591     4,665     4,865     4,623     2,861       425     1,694
 Interest (income) ex-
  pense, net............      (98)      270       690       643       762       113       584
 Other expense (income).       69      (363)     (203)      219      (563)     (102)     (129)
 Property impairment....      --        --        --      9,300       --        --        --
                          -------  --------  --------  --------  --------  --------  --------
                           29,873    39,777    47,793    63,813    52,457    13,360    16,633
                          -------  --------  --------  --------  --------  --------  --------
EARNINGS BEFORE TAXES...   18,918    18,929    10,748       467     9,236     2,816     2,001
                          -------  --------  --------  --------  --------  --------  --------
PROVISIONS FOR INCOME
 TAXES
 Current................      750       600       625       425       302       140        81
 Deferred...............    1,372     1,670       989      (341)    2,284       648       680
                          -------  --------  --------  --------  --------  --------  --------
                            2,122     2,270     1,614        84     2,586       788       761
                          -------  --------  --------  --------  --------  --------  --------
NET EARNINGS
 Before accounting
  changes...............   16,796    16,659     9,134       383     6,650     2,028     1,240
 Accounting changes:
 Deferred income taxes..      --        --        --      2,000       --        --        --
 Postretirement bene-
  fits, net of tax......      --        --        --       (656)      --        --        --
                          -------  --------  --------  --------  --------  --------  --------
                          $16,796  $ 16,659  $  9,134  $  1,727  $  6,650  $  2,028  $  1,240
                          =======  ========  ========  ========  ========  ========  ========
AVERAGE SHARES OUTSTAND-
 ING....................    9,556     9,769     9,796     9,797     9,808     9,800     9,822
                          =======  ========  ========  ========  ========  ========  ========
EARNINGS PER SHARE:
 Before accounting
  changes...............  $  1.76  $   1.71  $   0.93  $   0.04  $   0.68  $   0.21  $   0.13
 Accounting changes:
 Deferred income taxes..      --        --        --   $   0.20       --        --        --
 Postretirement bene-
  fits..................      --        --        --   $  (0.06)      --        --        --
                          -------  --------  --------  --------  --------  --------  --------
 Net earnings...........  $  1.76  $   1.71  $   0.93  $   0.18  $   0.68  $   0.21  $   0.13
                          =======  ========  ========  ========  ========  ========  ========
OPERATING DATA:
 EBITDA*................  $27,475  $ 32,048  $ 27,515  $ 30,534  $ 29,649  $  7,719  $  9,133
 Cash provided by oper-
  ating activities......   26,189    31,866    27,499    31,432    27,924     7,270     8,275
BALANCE SHEET DATA:
 Property and equipment,
  net...................  $79,027  $108,837  $122,505  $117,467  $146,491  $115,158  $145,529
 Total assets...........   91,348   120,474   133,975   126,792   156,944   124,993   155,065
 Long-term debt.........    3,000    15,000    20,000    13,500    37,000    10,500    34,500
 Stockholders' equity...   73,280    88,515    95,358    94,803    99,456    96,242   100,303
 Total debt-to-stock-
  holders' equity ratio.       4%       17%       21%       14%       37%       11%       34%
</TABLE>
- --------
*  Reflects earnings before taxes less other income, plus depreciation,
   depletion and amortization, property impairment, exploration, interest and
   other expenses. This data does not purport to reflect any measure of
   operations or cash flows.
 
                                       15
<PAGE>
 
                 SELECTED PRO FORMA CONSOLIDATED FINANCIAL DATA
 
  The following table sets forth selected unaudited pro forma consolidated
financial data of Barrett giving effect to the Merger under the pooling of
interests method of accounting and reflecting certain assumptions described in
the notes to the unaudited pro forma consolidated condensed financial
statements. The Selected Pro Forma Consolidated Statements of Income Data set
forth below assume the Merger was consummated as of October 1, 1991, and the
Selected Pro Forma Consolidated Balance Sheet Data set forth below assume the
Merger was consummated as of March 31, 1995. The pro forma consolidated
financial data is presented for illustrative purposes only and is not
necessarily indicative of the operating results or financial position that
would have occurred if the Merger had been consummated on the dates indicated,
nor is it necessarily indicative of future operating results or financial
position. The pro forma consolidated financial data has been derived from and
should be read in conjunction with the unaudited pro forma consolidated
condensed financial statements, including the notes thereto, appearing
elsewhere in this Joint Proxy Statement/Prospectus. See "THE MERGER--
Anticipated Accounting Treatment" and "UNAUDITED PRO FORMA CONSOLIDATED
CONDENSED FINANCIAL STATEMENTS."
 
                PRO FORMA CONSOLIDATED STATEMENTS OF INCOME DATA
 
<TABLE>
<CAPTION>
                                         YEARS ENDED DECEMBER 31,    SIX MONTHS
                                             AND SEPTEMBER 30,         ENDED
                                         --------------------------  MARCH 31,
                                          1992      1993     1994       1995
                                         -------  -------- --------  ----------
                                           (IN THOUSANDS, EXCEPT PER SHARE
                                                       AMOUNTS)
<S>                                      <C>      <C>      <C>       <C>
Revenues:
  Oil and gas production................ $65,167  $ 79,256 $ 79,270   $47,173
  Trading revenues......................  16,726    26,357   22,443    18,520
  Revenue from gas gathering............     279       271      252       442
  Interest income.......................     600       498      891       205
  Other income..........................      54       584       89        41
                                         -------  -------- --------   -------
                                          82,826   106,966  102,945    66,381
Operating expenses:
  Lease operating expense...............  26,864    30,056   28,229    16,973
  Cost of trading.......................  16,601    25,343   21,577    17,869
  Depreciation, depletion and
   amortization.........................  14,198    19,726   22,669    14,614
  General and administrative............   9,280    10,441   12,901     7,292
  Interest expense......................     716       656      768     1,402
  Other (income) expense................    (203)      219     (563)       79
                                         -------  -------- --------   -------
                                          67,456    86,441   85,581    58,229
                                         -------  -------- --------   -------
Income before income taxes..............  15,370    20,525   17,364     8,152
Provision for income taxes..............   5,790     5,985    5,157     2,842
                                         -------  -------- --------   -------
Net income from continuing operations... $ 9,580  $ 14,540 $ 12,207   $ 5,310
                                         =======  ======== ========   =======
Earnings per share
  Shares outstanding....................  22,468    23,644   24,667    24,868
                                         =======  ======== ========   =======
  Net income from continuing operations
   per share............................ $   .43  $    .61 $    .49   $   .21
                                         =======  ======== ========   =======
EBITDA*................................. $29,684  $ 40,409 $ 39,910   $23,963
                                         =======  ======== ========   =======
</TABLE>
- --------
*  Reflects income before income taxes less interest income, plus interest
   expense, plus depreciation, depletion and amortization expense. This data
   does not purport to reflect any measure of operations or cash flow.
 
See notes accompanying the unaudited Pro Forma Consolidated Condensed Financial
    Statements included elsewhere in this Joint Proxy Statement/Prospectus.
 
                                       16
<PAGE>

                   PRO FORMA CONSOLIDATED BALANCE SHEET DATA
 
<TABLE>
<CAPTION>
                                                                 AS OF MARCH 31,
                                                                      1995
                                                                 ---------------
                                                                 (IN THOUSANDS)
<S>                                                              <C>
                             ASSETS
Current assets:
  Cash and cash equivalents.....................................    $ 13,048
  Receivables...................................................      28,337
  Inventory, at lower of average cost or market.................         647
  Other current assets..........................................         834
                                                                    --------
    Total current assets........................................      42,866
Net property and equipment......................................     272,504
Other assets....................................................         150
                                                                    --------
                                                                    $315,520
                                                                    ========
              LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Accounts payable..............................................    $ 10,453
  Due to oil and gas property owners............................      16,492
  Accrued and other liabilities.................................       7,367
                                                                    --------
    Total current liabilities...................................      34,312
                                                                    --------
Other long-term liabilities.....................................       1,023
                                                                    --------
Post retirement benefits........................................         952
                                                                    --------
Long-term debt..................................................      65,500
                                                                    --------
Deferred income taxes...........................................      22,521
                                                                    --------
Stockholders' equity:
  Preferred stock...............................................         --
  Common stock..................................................         247
  Additional paid-in capital....................................      79,485
  Retained earnings.............................................     112,022
  Treasury stock, at cost.......................................        (542)
                                                                    --------
    Total stockholders' equity..................................     191,212
                                                                    --------
                                                                    $315,520
                                                                    ========
</TABLE>
 
See notes accompanying the unaudited Pro Forma Consolidated Condensed Financial
    Statements included elsewhere in this Joint Proxy Statement/Prospectus
 
                                       17
<PAGE>
 
                       COMPARATIVE PER COMMON SHARE DATA
                      OF BARRETT RESOURCES CORPORATION AND
                            PLAINS PETROLEUM COMPANY
 
  The following table sets forth per share data of Barrett and Plains on a
historical basis, and pro forma consolidated data for Barrett as if the Merger
had been effective for all periods presented. Pro forma information for Plains
is presented on a pro forma equivalent basis, which reflects the pro forma
consolidated per share amounts multiplied by the Exchange Ratio of 1.3. Pro
forma information gives effect to the Merger under the pooling of interests
method of accounting and reflects certain assumptions described in the notes to
the Unaudited Pro Forma Consolidated Condensed Financial Statements. The data
set forth below should be read in conjunction with the respective audited and
unaudited consolidated historical financial statements of Barrett and Plains,
including the respective notes thereto, and the Unaudited Pro Forma
Consolidated Condensed Financial Statements, including the notes thereto,
appearing elsewhere in this Joint Proxy Statement/Prospectus. See "AVAILABLE
INFORMATION," "INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE" and "UNAUDITED
PRO FORMA CONSOLIDATED CONDENSED FINANCIAL STATEMENTS."
 
<TABLE>
<CAPTION>
                                     HISTORICAL        UNAUDITED PRO FORMA
                                   -------------- -----------------------------
                                                    BARRETT         PLAINS
                                   BARRETT PLAINS CONSOLIDATED EQUIVALENT(1.3X)
                                   ------- ------ ------------ ----------------
<S>                                <C>     <C>    <C>          <C>
SIX MONTHS ENDED MARCH 31, 1995
  Income from continuing
   operations....................   $0.09  $ 0.30    $0.21          $ 0.27
  Book value as of March 31,
   1995..........................   $6.12  $10.21    $7.69          $10.00
YEAR ENDED SEPTEMBER 30, 1994 AND
 DECEMBER 31, 1994
  Income from continuing
   operations....................   $0.37  $ 0.68    $0.49          $ 0.64
YEAR ENDED SEPTEMBER 30, 1993 AND
 DECEMBER 31, 1993
  Income from continuing
   operations....................   $0.53  $ 0.04    $0.61          $ 0.79
YEAR ENDED SEPTEMBER 30, 1992 AND
 DECEMBER 31, 1992
  Income from continuing
   operations....................   $0.09  $ 0.93    $0.43          $ 0.56
</TABLE>
 
                                       18
<PAGE>
 
                     COMPARATIVE STOCK PRICES AND DIVIDENDS
 
  The Barrett Common Stock and the Plains Common Stock are listed and traded on
the NYSE (Symbols: BRR and PLP, respectively). Prior to November 29, 1994, the
Barrett Common Stock was traded on the NASDAQ National Market System
("NASDAQ/NMS") under the symbol "BARC." The following table sets forth for the
periods indicated the reported high and low sales prices per share of the
Barrett Common Stock through November 28, 1994 on the NASDAQ/NMS and thereafter
on the NYSE Composite Transactions Tape, and for the Plains Common Stock on the
NYSE Composite Transactions Tape. The following table also sets forth the cash
dividends paid by Plains on the Plains Common Stock for the periods indicated.
Barrett has not paid cash dividends on the Barrett Common Stock. The fiscal
year of Barrett currently ends on September 30 of each year. The fiscal year of
Plains ends on December 31 of each year.
 
<TABLE>
<CAPTION>
                                                      SALES PRICE
BARRETT COMMON STOCK                                  --------------
                                                      HIGH      LOW
                                                      ------   -----
<S>                                                   <C>      <C>      
Fiscal 1993
  First Quarter (ended December 31, 1992)............ $ 10 3/4 $  5 1/2
  Second Quarter (ended March 31, 1993)..............   12 7/8    8 3/8
  Third Quarter (ended June 30, 1993)................   16       11 3/8
  Fourth Quarter (ended September 30, 1993)..........   13 3/4    9 7/8
Fiscal 1994
  First Quarter (ended December 31, 1993)............ $ 13     $ 10
  Second Quarter (ended March 31, 1994)..............   14 3/8   10 3/8
  Third Quarter (ended June 30, 1994)................   16 1/2   13 1/4
  Fourth Quarter (ended September 30, 1994)..........   20       15 5/8
Fiscal 1995
  First Quarter (ended December 31, 1994)............ $ 22 3/4 $ 17 7/8
  Second Quarter (ended March 31, 1995)..............   21 3/4   16 7/8
  Third Quarter (through June 12, 1995)..............
<CAPTION>
                                                      SALES PRICE
PLAINS COMMON STOCK                                   --------------
                                                                          CASH
                                                      HIGH      LOW     DIVIDEND
                                                      ------   -----    --------
<S>                                                   <C>      <C>      <C>
Fiscal 1993
  First Quarter (ended March 31, 1993)............... $ 29 3/4 $ 24 7/8   $.06
  Second Quarter (ended June 30, 1993)...............   29       24 3/8    .06
  Third Quarter (ended September 30, 1993)...........   30 3/8   25 3/8    .06
  Fourth Quarter (ended December 31, 1993)...........   28       19 1/2    .06
Fiscal 1994
  First Quarter (ended March 31, 1994)............... $ 27 7/8 $ 21 3/8   $.06
  Second Quarter (ended June 30, 1994)...............   22 5/8   19 1/2    .06
  Third Quarter (ended September 30, 1994)...........   26 5/8   20 3/4    .06
  Fourth Quarter (ended December 31, 1994)...........   27 7/8   23 1/2    .06
Fiscal 1995
  First Quarter (ended March 31, 1995)............... $ 24     $ 21 3/8   $.06
  Second Quarter (through June 12, 1995).............
</TABLE>
 
  On May 2, 1995, the last trading day before the public announcement of the
execution of the Merger Agreement, the last sale prices of the Barrett Common
Stock and the Plains Common Stock, as reported on the NYSE Composite
Transactions Tape, were $23 1/4 per share and $24 per share, respectively.
Recent last sale prices of the Barrett Common Stock and the Plains Common Stock
as reported on the NYSE Composite Transactions Tape are set forth on the cover
page of this Joint Proxy Statement/Prospectus. Barrett and Plains stockholders
are urged to obtain current market quotations for the Barrett Common Stock and
the Plains Common Stock.
 
  DIVIDEND POLICY OF BARRETT FOLLOWING THE MERGER. Consistent with Barrett's
past practice, Barrett does not expect to pay cash dividends on the Barrett
Common Stock after the Merger.
 
                                       19
<PAGE>
 
                                  INTRODUCTION
 
  This Joint Proxy Statement/Prospectus is being furnished to stockholders of
Barrett in connection with the solicitation of proxies by the Barrett Board of
Directors for use at the Barrett Special Meeting to be held at the Brown Palace
Hotel, 321 Seventeenth Street, Denver, Colorado on Tuesday, July 18, 1995, at
11:00 a.m., Denver time, and at any adjournments or postponements thereof.
 
  This Joint Proxy Statement/Prospectus is also being furnished to stockholders
of Plains in connection with the solicitation of proxies by the Plains Board of
Directors for use at the Plains Special Meeting to be held at the Brown Palace
Hotel, 321 Seventeenth Street, Denver, Colorado, on Tuesday, July 18, 1995, at
9:00 a.m., Denver time, and at any adjournments or postponements thereof.
 
  At the Barrett Special Meeting, stockholders of Barrett will be asked to
approve the Charter Amendment and the Stock Issuance in connection with the
consummation of the transactions pursuant to the Merger Agreement, including
the Merger. At the Plains Special Meeting, stockholders of Plains will be asked
to approve and adopt the Merger Agreement and the Merger. A conformed copy of
the Merger Agreement appears as Annex I to this Joint Proxy
Statement/Prospectus.
 
  This Joint Proxy Statement/Prospectus also constitutes a prospectus of
Barrett with respect to up to    shares of Barrett Common Stock issuable to
Plains stockholders in the Merger pursuant to the Merger Agreement or upon
exercise of certain stock options of Plains which, pursuant to the Merger
Agreement and the terms of the related stock option plans, following the Merger
will constitute options to purchase shares of Barrett Common Stock upon the
terms set forth in such stock option plans and the Merger Agreement.
 
                         BARRETT RESOURCES CORPORATION
 
GENERAL
 
  Barrett is an independent oil and gas exploration and production company with
major emphasis in the Rocky Mountain region and Oklahoma. During fiscal 1994,
more than 96% of Barrett's total production was natural gas. Barrett's reserves
are located primarily in the Piceance, Wind River, Arkoma and Anadarko Basins.
 
  Barrett principally utilizes its own exploration staff to develop a geologic
concept into an exploration prospect. After the prospect is generated,
Barrett's land department attempts to acquire a large lease block in the area
of the prospect. Barrett's strategy is to develop prospects and to acquire
acreage in identified core areas of interest. Barrett will act as the operator
of its exploration or development drilling programs whenever possible. As of
March 31, 1995, Barrett was serving as operator for approximately 245 producing
wells, 32 shut-in wells, three wells that were drilling, three wells that were
being completed and 10 wells that were waiting on completion. In total, as of
March 31, 1995, Barrett had interests in 544 producing oil and natural gas
wells.
 
  Barrett was organized as a Colorado corporation in 1980 under the name
AIMEXCO Inc. In December 1983, AIMEXCO acquired Barrett Energy Company. In
1984, AIMEXCO changed its name to Barrett Resources Corporation, and in 1987
Barrett changed its state of incorporation from Colorado to Delaware.
 
  Barrett Fuels Corporation, a wholly owned subsidiary of Barrett, is engaged
in natural gas trading activities as well as natural gas marketing activities
on behalf of itself and others. See "--Gas Marketing and Trading."
 
  Unless otherwise indicated, references to the fiscal year of Barrett refers
to the latest 12 months ended September 30th.
 
PICEANCE BASIN PROJECT
 
  OVERVIEW. The Piceance Basin of northwestern Colorado is the area containing
the largest amount of Barrett's proved reserves and continues to be very
prominent in its capital spending plans. Fifty-one
 
                                       20
<PAGE>
 
percent of Barrett's fiscal 1994 reserve growth came from the Piceance Basin.
Barrett believes that it will have additional proved reserve growth in the area
due to increased drilling density and other activities. As of March 31, 1995,
Barrett's net daily production was approximately 26 MMcf of natural gas from
this area.
 
  Barrett drilled its first well in the Piceance Basin in 1984. As of March 31,
1995, Barrett owned and operated 255 gross (83.5 net) wells in the Piceance
Basin and had working interests in an additional 23 gross and three net non-
operated wells. Barrett has interests in approximately 152,859 gross (46,547
net) acres in this Basin. Barrett's activities in the Piceance Basin are
conducted primarily in the Rulison, Grand Valley and Parachute Fields. In
addition, Barrett has small projects in the DeBeque, Trailridge and Story Gulch
areas of the Piceance Basin.
 
  Barrett's current drilling activities in the Piceance Basin target primarily
the lenticular sands of the Williams Fork Formation of the Mesaverde group
("Mesaverde") which overlie the Cameo coal beds. Based on Barrett's operating
experience, an average Mesaverde natural gas well is expected to produce 1.5
Bcf of natural gas in the Grand Valley and Parachute Fields and 1.8 Bcf of
natural gas in the Rulison Field during the first 20 years of its life.
 
  As of March 31, 1995, Barrett had eight Mesaverde wells waiting on completion
and was operating two drilling rigs in the Piceance Basin. Each of these rigs
is capable of drilling a new Mesaverde well approximately every 25 days.
Depending on natural gas prices, a third and possibly a fourth rig may be added
to the program.
 
  Barrett has constructed and operates, on behalf of itself and others, the
Grand Valley Gathering System, which consists of approximately 175 miles of
pipeline and related facilities in the Piceance Basin project. In addition, in
December 1994, Barrett completed construction of a 16-inch, 27 mile pipeline
extension of its Piceance Basin gathering system and construction of a natural
gas processing plant. This pipeline extension enables Barrett to move natural
gas to three interstate pipelines and allows the transport of Barrett's natural
gas to mid-continent markets. Barrett also owns and operates a 30 mile natural
gas gathering system in the Washakie-Red Desert Basin of Wyoming, as well as
three smaller systems in other areas.
 
  In February 1995, the Colorado Oil and Gas Conservation Commission approved
40 acre increased well density (from 80 acres) within 81 sections in the
Piceance Basin, which Barrett estimates will add 299 potential locations for
infill drilling. The remainder of the area is already on statewide 40 acre
spacing. Barrett's engineering and geologic data indicate that, ultimately, it
may be desirable to down-space to increase density to 20 acres and possibly 10
acres in order to recover efficiently the natural gas reserves present in the
Mesaverde reservoirs. Barrett has not applied for increased density below 40
acres and the outcome of any such application, if made, is not predictable.
 
  During fiscal 1995, based on full-time use of two drilling rigs, Barrett
plans to drill or participate in 35 wells in the Piceance Basin with an
estimated net capital outlay to Barrett of $15.6 million. Also, during fiscal
1995, a recompletion program on numerous behind-pipe zones in 18 wells was
initiated. Barrett has identified another 54 wells to include in this program.
 
  RULISON FIELD. The Rulison Field produces from both the Wasatch and Mesaverde
Formations with wells drilled to depths varying from 1,200 to 2,500 feet in the
Wasatch and 7,500 to 8,500 feet in the Mesaverde Formation. As of March 31,
1995, Barrett as operator had drilled or acquired 93 wells in the Rulison
Field, with 67 wells currently producing and 25 wells either shut-in, waiting
on completion or completing. One Wasatch well has been plugged and abandoned.
All of Barrett's Mesaverde wells have been successfully completed. Barrett has
working interests ranging from 29% to 100%, with an overall average of 60%, in
approximately 35,840 gross acres in this area. As of May 22, 1995, two rigs are
engaged in drilling a Mesaverde development program in this area. Barrett
recently drilled and completed two new Wasatch wells in the field; both are
waiting on completion.
 
 
                                       21
<PAGE>
 
  In fiscal years 1994 and 1995, Barrett drilled the #1 Rulison Deep well to a
total depth of 14,236 feet to test the potential of the Mancos, Dakota,
Morrison and Entrada Formations. As of May 1, 1995, the Entrada, Morrison and
Dakota had been tested and proved to be non-commercial. If the well proves to
be non-commercial in the Mancos, Barrett anticipates completing the well in the
Mesaverde.
 
  GRAND VALLEY FIELD. The Grand Valley Field produces natural gas primarily
from the Mesaverde with wells drilled to depths ranging from 6,000 to 7,500
feet. As of March 31, 1995, Barrett as operator had drilled 84 wells, with 75
wells currently producing and four wells shut-in. Barrett has an average 29.5%
working interest in approximately 29,440 gross acres in this area.
 
  PARACHUTE FIELD. The Parachute Field produces from sandstone reservoirs in
the Wasatch and Mesaverde with wells drilled to depths varying from 1,200 to
1,800 feet in the Wasatch and 6,000 to 7,500 feet in the Mesaverde. As of March
31, 1995, Barrett had drilled 77 wells in the Parachute Field, with 72 wells
producing. Barrett is operator of the majority of the wells in this field.
Barrett has a 29.5% working interest in approximately 24,320 gross acres in
this area.
 
  Barrett recently drilled two new Wasatch wells in the Parachute Field, with
one well producing and one waiting on completion.
 
WIND RIVER BASIN
 
  OVERVIEW. In fiscal 1994, Barrett began a focused exploration program in the
Cave Gulch area of the eastern Wind River Basin of Wyoming. The primary
reservoir target in this program is a thick section of lenticular sandstones in
the Fort Union and Lance Formations. Barrett drilled the Cave Gulch Federal
Unit #1, which was completed for 9.7 MMcf of natural gas per day and 116
barrels of condensate per day in December 1994.
 
  As of March 31, 1995, Barrett owned interests in 13,035 gross (5,834 net)
acres in the Cave Gulch area. This total includes 440 gross (413 net) acres in
the Cave Gulch Federal Unit. Barrett owns a 94% working interest in the Unit.
 
  Simultaneously with its development program in the Cave Gulch Unit, Barrett
continues its exploration program along the Owl Creek Thrust and throughout
other areas in the Wind River Basin. Barrett has identified 11 active prospect
areas and has acquired an additional 28,835 gross (23,973 net) acres on these
new prospects, excluding the Cave Gulch area.
 
  CAVE GULCH UNIT DISCOVERY. Barrett drilled the Cave Gulch Federal Unit #1 to
a total depth of 6,902 feet and confirmed that a major structure extended
beneath the Owl Creek Thrust. The discovery is productive in the Ft. Union and
Lance sandstones. The well penetrated 481 feet of potential pay over a nearly
2,200 foot gross natural gas bearing interval and was still in natural gas
bearing Lance sands when drilling was terminated due to lease timing
requirements. As of May 22, 1995, 246 feet of net pay was open to the wellbore
and producing 10.2 MMcf of natural gas and 102 barrels of condensate per day.
 
  Barrett has drilled two development wells which offset the Cave Gulch #1 and
intends to drill 14 more wells during 1995 and 1996. The Cave Gulch Federal
Unit #4 was drilled to a depth of 9,350 feet and encountered 507 feet of net
pay in the Lance Formation on the eastern flank of the structure nearly 500
feet downdip from the Cave Gulch #1. An interval containing 71 feet of
indicated net pay tested 2.7 MMcf of natural gas per day. A number of other
zones will be tested prior to completion. The second development well, the Cave
Gulch Unit #9, was completed at a total depth of 8,951 feet through a nearly
4,200 foot interval of natural gas bearing sandstones in the Fort Union and
Lance Formations.
 
 
                                       22
<PAGE>
 
  In fiscal 1995, Barrett plans to drill a 13,000 foot Mesaverde test on the
high part of this structure, which has not been tested previously. Barrett will
consider drilling twin wells to some of the planned development wells to
accelerate production from the lower Lance and Ft. Union Formations.
 
  Barrett recently completed a proprietary 22-square mile 3-D seismic survey.
This survey is expected to better define the Ft. Union and Lance Formations for
development purposes and possible stepouts. Equally important, the 3-D siesmic
survey will image deeper horizons, including the Mesaverde, Frontier, Muddy,
Lakota, Tensleep and Madison Formations for future exploratory potential.
 
WYOMING OVERTHRUST
 
  OVERVIEW. Barrett has an active exploration effort in the Wyoming Overthrust
of southwestern Wyoming. The 1,000 foot thick Nugget sandstone is the primary
objective and the overlying Twin Creek limestone is a secondary objective.
Barrett is currently pursuing the Nighthawk and Emigrant prospects along this
trend.
 
  NIGHTHAWK PROSPECT. Barrett has obtained access from an industry partner to a
35-square mile 3-D seismic survey covering the Nighthawk Prospect located
immediately north of the East Painter Reservoir Field. Barrett expects to
commence drilling a 13,000 foot Nugget test in July 1995. The well would cost
an estimated $2.2 million to drill and complete.
 
  Barrett will have a 100% working interest before payout and a 70% working
interest after payout in the first well. Barrett controls 1,360 gross acres in
the Nighthawk area and has an additional 444 net acres committed through farm-
outs and an additional 360 net acres requested.
 
  EMIGRANT PROSPECT AND INITIAL WELL. Barrett participated with a 6.25% working
interest in the Helmerich and Payne #1-11 Sealind well, the initial well on the
"North Lobe" of the Emigrant Prospect. The well was completed as a dry hole in
January 1995.
 
  In 1994, Barrett and its partners acquired a 33-square mile 3-D seismic
survey over the area primarily to image the "South Lobe" prospect at Emigrant.
The data is currently being processed. Confirmation of a "South Lobe" structure
may lead to a possible 1995 Nugget exploration test. Barrett currently owns
3,075 gross (195 net) acres in the Emigrant Prospect area.
 
GREATER GREEN RIVER BASIN
 
  WASHAKIE/RED DESERT BASIN. Barrett operates 16 upper and lower Almond wells
drilled during 1992 and 1993 in the Wamsutter area of the Washakie-Red Desert
Basins. Barrett is considering drilling additional development wells in the
area, based on successful new third party drilling adjacent to certain of
Barrett's acreage.
 
  MOXA ARCH AND NORTHWEST GREEN RIVER BASIN. In addition to the Washakie-Red
Desert Basin, Barrett has a considerable geologic data base in the Greater
Green River Basin, specifically in the Moxa Arch and Northwest Green River
Basin.
 
  As of March 31, 1995, Barrett owned interests in 7,347 gross (3,588 net)
acres in the Greater Green River Basin.
 
OKLAHOMA PROJECT
 
  Barrett began its Oklahoma operations in November 1992, with a successful Red
Oak Field development project in the Arkoma Basin. Barrett continues to pursue
and develop other prospects both in the Arkoma
 
                                       23
<PAGE>
 
and Anadarko Basins. Barrett's Tulsa district office is primarily responsible
for generating exploration and development projects in these basins. As of
March 31, 1995, Barrett had drilled or participated in the drilling of 105
wells in Oklahoma, of which 72 wells were producing natural gas, 19 were in
various stages of completion, nine wells were drilling and five wells had been
plugged and abandoned.
 
  ARKOMA BASIN PROJECT. During fiscal 1994 and the first half of fiscal 1995,
Barrett drilled or participated in the drilling of 28 wells in its five main
focus areas of the Arkoma Basin: Red Oak Field, Limestone Ridge, White Ranch,
Wilburton Field and Choctaw 3-D seismic area.
 
  In the Red Oak Field, Barrett has drilled or participated in the drilling of
36 wells, all productive, since November 1992. Barrett's working interests
after payout in this field range from 1.3% to 45%.
 
  In the Limestone Ridge area, Barrett had drilled or participated in the
drilling of five wells as of May 22, 1995, with four wells producing and one
well completed and waiting on pipeline connection. Barrett plans to drill at
least one more well in the Limestone Ridge area during fiscal 1995. Barrett's
working interests after payout in these wells range from 30% to 88%.
 
  In the White Ranch area, Barrett drilled or participated in the drilling of
four wells during fiscal 1994, with working interests after payout ranging from
12% to 67%. All four of these natural gas wells are presently producing. As of
March 31, 1995, Barrett was drilling a fifth well in this project.
 
  In the Wilburton Field area, during fiscal 1994, Barrett completed an
acquisition of six producing wells and drilled one well. Barrett's working
interests after payout in the wells range from 1% to 61%. Along with the
producing wells, Barrett also acquired leasehold interests that it plans to
develop during fiscal years 1995 and 1996.
 
  Also in the Wilburton Field, during fiscal 1995, Barrett has participated in
the drilling of two additional wells and plans to drill or participate in at
least two more Spiro wells.
 
  In fiscal 1994, Barrett entered into an agreement with another company which
allows Barrett to prospect on the other party's large acreage holdings in the
Frontal Choctaw Thrust area using a 3-D seismic survey developed by that party
and another company. The main natural gas producing zones in this area are the
Middle Atoka Sandstone, the Spiro Sandstone and the Wapanucka Limestone.
Barrett participated in one well in this area during fiscal 1994 and plans to
drill at least two wells in this area during fiscal 1995.
 
  ANADARKO BASIN PROJECT. During fiscal 1994, Barrett drilled or participated
in 23 wells in the Anadarko Basin. Prospect generation was concentrated in
three main areas: the Watonga-Chickasha Trend, the Strong City Red Fork Play
and the Cement Field area. Working interests after payout in these wells range
from 2% to 79%.
 
  In fiscal 1995, Barrett will continue its activity in the Anadarko Basin,
with current plans calling for Barrett to drill or participate in more than 50
wells in the area, 28 of which had been commenced or completed as of March 31,
1995.
 
  The Watonga-Chickasha Trend produces predominantly from Morrow and Springer
sandstones. Barrett drilled or participated in the drilling of 12 wells in the
Watonga-Chickasha Trend during fiscal 1994 and seven wells during the first
half of fiscal 1995. Barrett's working interests after payout range from 2% to
79%. Of these 19 wells, as of March 31, 1995, 10 were producing natural gas,
five wells were waiting on pipeline connection, two wells were waiting on
completion and two wells were scheduled to be plugged and abandoned. During the
remainder of fiscal 1995, Barrett intends to participate in drilling 15
additional wells in this area.
 
  The Strong City Red Fork play is in an active drilling area that covers
approximately 750 square miles in Roger Mills and Custer Counties in western
Oklahoma. The targets are the Red Fork, Prue and
 
                                       24
<PAGE>
 
Skinner sandstones at depths ranging from 11,000 feet to 13,500 feet across the
region. Barrett drilled or participated in 18 wells in this area from the
beginning of fiscal 1994 through March 31, 1995. Of these 18 wells, 10 are
producing, one is waiting on pipeline connection, two are waiting on
completion, four are drilling and one was plugged and abandoned. Barrett's
working interests after payout in these wells range from 1% to 25%. The Strong
City Red Fork Play will be an important part of Barrett's activity in the
Anadarko Basin during fiscal 1995, with current plans calling for drilling or
participating in 30 wells.
 
  Barrett is participating with industry partners in the drilling and
development of Wade, Medrano, Marchand, Culp, Melton and Springer sandstones in
the Cement Field. The structural complexity of these formations creates a
higher degree of risk, but provides targets with high porosity and
permeability. During fiscal 1994, Barrett participated in four wells in the
Cement Field, with working interests after payout ranging from 3% to 31%. Of
the four wells, three are producers and one was plugged and abandoned.
 
  Barrett has participated in five wells in this area during the first half of
fiscal 1995. Of the five, one is producing, two are being completed, one is
waiting on completion and one was plugged and abandoned. Barrett plans to
participate in two more wells in this area during fiscal 1995, and is pursuing
interests in other prospects which have been generated.
 
PRODUCTION
 
  The table below sets forth information with respect to Barrett's producing
oil and natural gas properties for the periods indicated:
 
<TABLE>
<CAPTION>
                                                             SIX MONTHS ENDED
                                YEAR ENDED SEPTEMBER 30,         MARCH 31,
                              ----------------------------- -------------------
                                1992      1993      1994      1994      1995
                              --------- --------- --------- --------- ---------
<S>                           <C>       <C>       <C>       <C>       <C>
QUANTITIES PRODUCED AND SOLD
 Oil and Condensate (Bbls)...    55,200    74,890    53,700    27,330    39,900
 Gas (Mcf)................... 3,502,000 7,214,300 9,069,000 4,464,000 6,674,000
AVERAGE SALES PRICE
 Oil and Condensate ($/Bbl)..    $19.09    $17.59    $14.34    $13.34    $15.15
 Gas ($/Mcf).................    $ 1.59    $ 1.89    $ 1.85    $ 2.03    $ 1.46
AVERAGE PRODUCTION COST PER
 MCFE(1).....................    $ 0.36    $ 0.36    $ 0.38    $ 0.37    $ 0.35
</TABLE>
- --------
(1) Includes lease operations expense, production and property taxes,
    transportation and processing payments.
 
PRODUCTIVE WELLS AND ACREAGE
 
  The productive wells and developed acreage in which Barrett owned a working
interest as of March 31, 1995 are described in the following table:
 
<TABLE>
<CAPTION>
                                          PRODUCTIVE WELLS
                                       ----------------------
                                       OIL WELLS  GAS WELLS   DEVELOPED ACREAGE
                                       --------- ------------ ------------------
                                       GROSS NET GROSS  NET     GROSS     NET
                                       ----- --- ----- ------ --------- --------
<S>                                    <C>   <C> <C>   <C>    <C>       <C>
Piceance Basin, CO...................    --   --  278    86.5    88,567   24,157
Wind River, WY.......................    --   --    3     2.8     6,359    1,529
Arkoma Basin, OK.....................    --   --   92    23.9     8,424    1,921
Anadarko Basin, OK...................    --   --   71    11.9    11,114    2,344
Washakie-Red Desert Basin, WY........    --   --   15     2.8     5,411    1,829
Miscellaneous Properties.............    76  3.9    9    1.14     8,556    1,383
                                        ---  ---  ---  ------ --------- --------
 Total...............................    76  3.9  468  134.18   128,431   33,163
                                        ===  ===  ===  ====== ========= ========
</TABLE>
 
                                       25
<PAGE>
 
DRILLING ACTIVITY
 
  The following table summarizes Barrett's natural gas and oil drilling
activities, all of which were located in the continental United States, during
the periods indicated:
 
<TABLE>
<CAPTION>
                              YEAR ENDED SEPTEMBER 30,       SIX MONTHS ENDED MARCH 31,
                         ---------------------------------- ------------------------------
                            1992       1993        1994         1994            1995
                         ---------- ----------- ----------- -------------- ---------------
                         GROSS NET  GROSS  NET  GROSS  NET   GROSS   NET    GROSS   NET
                         ----- ---- ----- ----- ----- ----- ------- ------ ------- -------
<S>                      <C>   <C>  <C>   <C>   <C>   <C>   <C>     <C>    <C>     <C>
WELLS DRILLED
Exploratory
 Oil....................    2  1.00   --     --   --     --      --     --      --      --
 Gas....................   --    --   --     --   --     --      --     --      --      --
 Non-productive.........    8  3.57    6   2.99   --     --      --     --      --      --
                          ---  ----  ---  -----  ---  -----  ------ ------  ------ -------
 Total..................   10  4.57    6   2.99   --     --      --     --      --      --
                          ===  ====  ===  =====  ===  =====  ====== ======  ====== =======
Development
 Oil....................   --    --    2   0.78    3   0.50       2    0.4      --      --
 Gas....................   15  5.98   60  20.72   72  24.13      29    8.6      55    18.6
 Non-productive.........    2  0.98    3   0.94    2   0.44       2    0.4       5     0.9
                          ---  ----  ---  -----  ---  -----  ------ ------  ------ -------
 Total..................   17  6.96   65  22.44   77  25.07      33    9.4      60    19.6
                          ===  ====  ===  =====  ===  =====  ====== ======  ====== =======
</TABLE>
  In addition, Barrett was participating in 10 gross (1.81 net) wells which
were in the process of being drilled at March 31, 1995.
 
RESERVES
 
  The table below sets forth estimates of quantities of Barrett's proved
reserves, all of which were located in the continental United States, as
prepared by Barrett and audited by Ryder Scott Company, independent petroleum
engineers, and the present value of estimated future net revenues from these
reserves on a non-escalated basis discounted by 10% per year as of the end of
each of the last three fiscal years and the first six months of fiscal 1995:
<TABLE>
<CAPTION>
                                                   SEPTEMBER 30,
                                              ------------------------ MARCH 31,
                                               1992    1993     1994     1995*
                                              ------- ------- -------- ---------
<S>                                           <C>     <C>     <C>      <C>
Estimated Proved Gas Reserves (Bcf).........       49      62      149      226
Estimated Proved Oil Reserves (MMbls).......      0.4     0.3      0.5      0.9
Estimated Proved Reserves in Gas Equivalents
 (Bcfe).....................................   51,903  64,096  152,110  231,321
Prices as of March 31 or September 30, for
 Oil ($/Bbl)................................  $ 19.74 $ 17.30 $  13.96 $  16.10
Prices as of March 31 or September 30, for
 Gas ($/Mcf)................................  $  1.85 $  2.00 $   1.54 $   1.23
Present Value of Estimated Future Net
 Revenues (before future income
 tax expense) ($ in millions)...............  $  36.5 $  48.2 $   84.9 $  102.8
</TABLE>
- --------
*  Barrett's annual reserve reports are prepared as of September 30, which is
   the last day of Barrett's fiscal year, and are reviewed by Ryder Scott
   Company, independent petroleum engineers. In addition, Barrett has prepared
   a reserve report as of March 31, 1995 (the "March Report"), which also has
   been reviewed by Ryder Scott Company. The review letters of Ryder Scott
   Company concerning Barrett's reserve reports as of September 30, 1994 and
   March 31, 1995 are included as exhibits to the Registration Statement of
   which this Joint Proxy Statement/Prospectus is a part. In preparing the
   March Report, Barrett used estimated production for the period from October
   1, 1994 to March 31, 1995 and did not undertake downward and upward
   revisions to the September 30, 1994 estimated reserve quantities, except
   with respect to properties located in the Cave Gulch and Rulison Field
   areas.
 
  Reference should be made to the Supplemental Oil and Gas Information,
included herein, for additional information pertaining to Barrett's estimated
proved oil and gas reserves.
 
UNDEVELOPED ACREAGE
 
  WORKING INTERESTS. Barrett's working interests in undeveloped acreage as of
March 31, 1995 are summarized in the following table:
<TABLE>
<CAPTION>
                                                          WORKING INTEREST ACRES
                                                          ----------------------
                                                             GROSS       NET
                                                          ----------------------
<S>                                                       <C>         <C>
STATE OF LOCATION
Colorado (Piceance Basin)...............................       64,292     22,390
North Dakota (Williston Basin)..........................       11,567      3,364
Oklahoma (Arkoma and Anadarko Basins)...................        8,572      5,766
Wyoming (Wind River, Washakie-Red Desert, Overthrust)...       54,895     33,892
Texas (Permian Basin)...................................        1,281      1,017
                                                          ----------- ----------
 Total..................................................      140,607     66,431
                                                          =========== ==========
</TABLE>
 
 
                                      26
<PAGE>
 
  Substantially all of the leases summarized in the preceding table will expire
at the end of their respective primary terms, unless production has been
obtained from the acreage subject to the lease prior to that date, in which
event the lease will remain in effect until the cessation of production. The
following table sets forth the gross and net acres subject to leases summarized
in the preceding table that will expire during the periods indicated:
 
<TABLE>
<CAPTION>
                                                                  ACRES EXPIRING
                                                                  --------------
                                                                   GROSS   NET
                                                                  ------- ------
<S>                                                               <C>     <C>
Twelve Months Ending:
 December 31, 1995...............................................  16,599  6,114
 December 31, 1996...............................................  37,203 10,994
 December 31, 1997...............................................  29,254 12,228
 December 31, 1998 and later.....................................  57,551 37,092
                                                                  ------- ------
   Total......................................................... 140,607 66,431
                                                                  ======= ======
</TABLE>
 
  OVERRIDING ROYALTY INTERESTS. Barrett owns overriding royalty interests
covering in excess of 14,000 gross acres. The majority of these overriding
royalty interests are within a range of approximately 0.5% to 2.5%.
 
GAS MARKETING AND TRADING
 
  Barrett's natural gas marketing and trading activities consist of marketing
Barrett's own production, marketing the production of others from wells
operated by Barrett, and natural gas trading activities that consist of the
purchase and resale of natural gas.
 
  Barrett has entered into a number of gas sales agreements on behalf of itself
and its industry partners with respect to the sale of gas from its properties
in each of the Arkoma Basin, Piceance Basin, Wind River Basin, Anadarko Basin
and Washakie-Red Desert Basin. These contracts vary with respect to their
specific provisions, including price, quantity and length of contract. As of
March 31, 1995, less than 5% of Barrett's production was committed to gas sales
contracts that had fixed prices. Barrett believes that it has sufficient
production from its properties to meet its delivery obligations under its
existing gas sales contracts.
 
  During the fiscal year ended September 30, 1994, revenues from trading
activities, which includes the cost of gas purchased or sold for trading
purposes, were $22.4 million representing 54.4 percent of Barrett's
consolidated revenues. Gross profits from trading activities during fiscal year
1994 and the first six months of fiscal year 1995 were approximately $0.9
million and $0.7 million, respectively. During the fiscal year ended September
30, 1994, various entities affiliated with Questar Corporation, through their
gas purchase and sales activity with Barrett, accounted for more than 14% of
Barrett's total revenues. Barrett believes it would be able to locate alternate
customers in the event of the loss of this customer.
 
  As a result of its gas trading activities, Barrett may from time to time have
gas purchases or sales commitments without corresponding contracts to offset
these commitments, which could result in losses to Barrett. Barrett currently
attempts to control and manage its exposure to these risks by monitoring and
hedging its trading positions as it deems appropriate and by having Barrett's
financial officers and Chief Executive Officer review significant trades or
positions before they are committed to by trading personnel.
 
                            PLAINS PETROLEUM COMPANY
 
  Plains is an independent oil and gas exploration and production company with
interests in 653 producing natural gas wells and 853 producing oil wells
located on approximately 344,500 gross (240,500 net) acres held by production
with estimated proved reserves of 312.5 Bcf of natural gas and 11 million
barrels of oil as of December 31, 1994. These reserves are located in the lower
48 states, principally in the Kansas and Oklahoma portions of the Hugoton
Field, the Permian Basin of west Texas and southeast New Mexico, the Powder
River and Green River Basins of Wyoming, and Louisiana state waters.
 
                                       27
<PAGE>
 
  Plains was incorporated as a wholly owned subsidiary of K N in November 1983
for the purpose of acquiring ownership of substantially all of K N's oil and
natural gas producing properties. On September 13, 1985, K N distributed the
Plains Common Stock held by it to the K N shareholders, which resulted in K N
no longer holding an ownership position in Plains and in the trading of the
Plains Common Stock on the NYSE.
 
  In the first quarter of 1995, Plains produced approximately 7.4 Bcf of
natural gas and approximately 405,000 barrels of oil, increases of
approximately 21% and 36%, respectively, as compared with natural gas
production and oil production in the first quarter of 1994. The increased
production was due principally to new natural gas wells placed on production in
the Ship Shoal Block 45 Field in Louisiana state waters and a Morrow well
drilled in Eddy County, New Mexico, as well as oil and natural gas production
from properties acquired on November 1, 1994 from Anadarko Petroleum
Corporation.
 
SOUTHWEST KANSAS, OKLAHOMA AND NORTHEAST COLORADO
 
  Based on the number of operated wells, Plains is the sixth largest operator
in the Kansas Hugoton Field. Plains operates 275 wells in the Field and owns
interests in 39 non-operated wells. These wells produce natural gas from the
Chase group at depths of approximately 2,800 feet. Prior to 1987, the Kansas
Hugoton Field was developed with one well per 640 acre proration unit. In 1987,
the Kansas Corporation Commission ("KCC"), which regulates production from the
Field, issued an order permitting the drilling of a second, or infill, well on
each Chase proration unit. A second well has not been added to 55 of the 165
units operated by Plains. Most of the units without an infill well are near the
edges of the Field where the formation is not as thick and the potential for
water encroachment is greater. To enhance the economic potential of these
units, Plains is testing horizontal drilling technology as a method to obtain
additional production in lieu of attempting to drill a second vertical well.
 
  Plains also operates 49 Panoma-Council Grove natural gas wells and owns
interests in 17 others. The Panoma formation underlies the Chase at a depth of
approximately 2,900 feet. Plains also has working interests in five additional
Panoma-Council Grove locations, which are non-operated. The Panoma-Council
Grove is not covered by the KCC's order permitting infill wells in the Chase
group.
 
  Most of Plains' natural gas produced in southwest Kansas is sold to K N under
a long-term contract. The contract provides that, during 1995, Plains will sell
to K N 14 Bcf of natural gas at a weighted average wellhead price of $1.80 per
MMBtu. The balance of Plains' natural gas production (including approximately
2.5 Bcf released from the K N contract in 1995) in southwest Kansas will be
sold to K N and third parties on a spot market basis. The contract with K N
provides for annual price redetermination. Negotiations for the 1996 price for
natural gas sold under the contract are expected to begin in the fall of 1995.
Because negotiations with K N take place on an arms'-length basis, the price
for 1996 may be more or less favorable than in 1995.
 
  Over the last two years, Plains has installed an automation system on 316
wells in southwest Kansas and added compression on the gathering system to
which many of its wells are connected. These two activities increase control,
while lowering wellhead pressures to meet production allowables and further
improve reservoir management. An additional 2,200 horsepower field compressor
station has been installed and, when fully operational, is expected to enhance
deliverability from Plains' wells.
 
  In the Oklahoma panhandle, Plains operates 30 Guymon-Hugoton wells and 41
Camrick wells and owns interests in 16 non-operated wells. Natural gas produced
from these wells is sold on the spot market.
 
  Plains also has an exploratory program in the Anadarko Basin to test the
Hunton formation at depths of 7,000 to 13,000 feet. Plains has purchased leases
and non-proprietary seismic data, identified lead areas, shot proprietary
seismic, drilled one prospect that was not productive and is preparing to drill
a second prospect, while two other prospects await further seismic processing.
Plains plans to obtain an industry partner and drill these latter three
prospects during the 1995 and 1996 calendar years.
 
                                       28
<PAGE>
 
  In Yuma County, Colorado, near the Colorado-Kansas state line, Plains has
working interests ranging from 6% to 100% in 66 wells in seven Niobrara chalk
natural gas fields, including Beecher Island, Schramm, Republican and
Buckboard. Plains has working interests in approximately 17,000 gross
undeveloped or under-developed leasehold acres in this area. An 80 acre infill
drilling program is currently in progress. In 1994, four successful development
wells were drilled, and 19 more wells are planned in 1995.
 
  Total capital spending for these areas in 1995 is estimated to be
approximately $5 million, of which approximately $1 million will be spent on
exploration, approximately $2.7 million on development drilling and
approximately $1.3 million on production facilities.
 
GULF OF MEXICO
 
  Since 1991, Plains has focused more of its activities in the Gulf of Mexico
by participating in projects with established Gulf of Mexico operators. The
availability of extensive 3-D seismic coverage over most of the Outer
Continental Shelf, the frequency of lease sales and the turnover of expiring
leases make the Gulf attractive as a new core growth area.
 
  In 1992, Plains participated in the drilling of a discovery well completed in
the Cris K formation in shallow Louisiana state waters on Ship Shoal Block 45.
This field was placed on production in 1993 after a development well was
completed and production facilities were constructed. Three additional
development wells were completed and placed on production in 1994. Together, in
May 1995, the five wells produced an average of 22.2 MMcf of natural gas and
501 barrels of condensate per day. Plains owns a 33.3% working interest in this
field. An additional development well is expected to be drilled in 1995.
 
  Plains is currently participating with a 33.3% working interest in a well
begun on May 13, 1995 to test the Pleistocene Lenticulina formation on Ship
Shoal Blocks 275/292 (approximately 232 feet water depth). This prospect, which
was identified with 3-D seismic data, is operated by Meridian Oil, Inc. and is
expected to reach target depth in June 1995.
 
  In the onshore Gulf area, Plains is currently participating with a 29.8%
working interest in Santa Fe Energy's Schoenfeld #2 development well, a 12,300-
foot Wilcox test in the Deckers Prairie Field near Houston, Texas. Completion
of this well is expected in June 1995.
 
  Capital spending in 1995 in this area is estimated to be approximately $8
million, with approximately $6.1 million scheduled for exploration and
approximately $1.9 million targeted for development drilling.
 
PERMIAN BASIN
 
  Plains has operated in the Permian Basin in west Texas and southeast New
Mexico since 1988 when it acquired the properties of Midland Resources, Inc.
Through additional acquisitions, exploitation and exploration efforts and joint
drilling ventures, Plains has continued to expand operations in this Basin. It
owns interests in and operates 196 oil wells and 12 natural gas wells, and owns
interests in 153 oil wells and two natural gas wells which are non-operated.
These wells are located in 21 fields in Texas and 12 fields located in New
Mexico.
 
  This area presents opportunities for adding production and reserves through
the use of modern exploration such as 3-D seismic surveys and improved
secondary and tertiary recovery techniques. In the past two years, Plains'
growth in the Permian Basin has been through new drilling projects and joint
ventures. The following four examples illustrate Plains' diverse strategies in
this area.
 
  Plains acquired its interest in the Teague Field in Lea County, New Mexico in
August 1991. After producing oil from the shallow Blinebry and Queen formations
for two years, Plains established production from the deeper Simpson-McKee
formation in 1993. Plains now has a 100% working interest in
 
                                       29
<PAGE>
 
three Simpson-McKee wells that, in May 1995, together produced over 220 barrels
of oil and 116 Mcf of natural gas per day. A fourth Simpson-McKee well is being
completed, and a fifth well currently is being drilled. Plains is evaluating
installation of a waterflood in this field.
 
  In 1994, Plains entered into a joint venture with OXY U.S.A., Inc. to improve
production from oil units in Ector County, Texas through redevelopment of
existing waterfloods. Plains pays 80% of OXY's costs for the redevelopment and
receives 80% of the revenues from each of the first two units until it has
recovered 125% and 150% of its investment, respectively, at which time Plains'
interest will convert to a 50% working interest. In May 1995, two of these
redeveloped fields produced 209 barrels of oil per day net to Plains' interest.
 
  Plains participated in the drilling of five successful exploratory wells on
prospects identified with 3-D seismic data in 1994. The most significant
discovery was the Sean Andrew Field in Dawson County, Texas, in which Plains
owns a 10% working interest, and in which four wells have now been completed
and are producing from Pennsylvanian Reefs. In addition, a fifth well is being
completed in the Sean Andrew Field. Three additional Pennsylvanian Reef wells
and three deeper Fusselman wells are planned in west Texas this year.
 
  Earlier in 1995, Plains joined in an exploration project of the South
Dollarhide area, a prospective, multi-pay (Devonian, Ellenberger and Clearfork)
play in Winkler County, Texas. With control of approximately 7,800 gross acres,
Plains and its partners conducted a 19 square mile 3-D seismic survey. As
operator with a 33.3% working interest, Plains anticipates drilling a Clearfork
or Devonian oil test on the acreage in the third quarter of 1995.
 
  Capital spending in 1995 in this area is estimated to be approximately $14
million, with approximately $1.4 million scheduled for exploration and
approximately $3.4 million targeted for development drilling and approximately
$9.2 million for secondary and tertiary recovery activities.
 
WYOMING AND THE ROCKY MOUNTAINS
 
  In the Powder River Basin of northeast Wyoming, Plains has conducted 31 3-D
seismic surveys to develop exploration prospects and enhance secondary and
tertiary oil recovery projects. Plains has also used new technology, such as an
alkaline surfactant polymer ("ASP") flood to improve oil recoveries. Plains
operates one of two ASP floods in the Powder River Basin. Presently, Plains
operates in 16 fields in the Powder River Basin and has interests in an
additional 20 fields.
 
  In 1989, Plains began participation in a Minnelusa exploratory program in the
Powder River Basin resulting in the discovery of the Cambridge Field in
Campbell County. Subsequently, the field was unitized and is the location of a
successful ASP flood. The unit, in which Plains holds a 74.5% working interest,
produced over 1,000 barrels of oil per day in May 1995.
 
  Since 1989, Plains has continued to successfully utilize 3-D seismic to more
efficiently develop and enhance primary and secondary recovery of oil from the
Minnelusa as well as other prospective formations in the Powder River Basin.
Plains has ongoing development projects in the North Adon Road, Rozet
Minnelusa, West Rozet, Rozet Muddy, East Moran, Wallace and South Rozet Field
areas.
 
  To build its asset base, Plains has made a number of acquisitions, the most
recent of which was completed on November 1, 1994, when Plains purchased for
$22.3 million interests in 21 fields, primarily in Wyoming. As of May 1995,
these properties produced in excess of 800 barrels of oil and 4 MMcf of natural
gas per day net to Plains. Two properties that were a part of this acquisition,
Spearhead Ranch Field and the Powell Field, are located in the southern Powder
River Basin and contain additional development drilling, re-completion and
secondary recovery opportunities. Nine Sussex and Frontier-Dakota development
locations are scheduled to be drilled during the 1995 and 1996 calendar years.
As part of this acquisition, for an additional $2 million Plains also acquired
leases covering over 50,000 undeveloped acres and an interest in an oil
pipeline.
 
                                       30
<PAGE>
 
  In 1994, Plains became active in the Green River Basin as part of a strategy
to join in the Basin-centered gas play evolving throughout this area. Plains
elected to participate with other companies that have extensive acreage
positions with eight to ten year lease terms. In addition, Plains' acquisition
program has added to its producing properties and acreage inventory in the
greater Green River Basin. Plains has working interests ranging from 26% to 62%
in 10 producing oil and natural gas wells in the Whiskey Springs and Taylor
Ranch Fields on the south end of the Moxa Arch in southwest Wyoming. Plains
plans to participate in drilling three or more 15,000 foot Frontier-Dakota
development wells in this area, with the first scheduled to begin drilling in
August 1995. During 1994, Plains drilled a successful Mesaverde exploration
well in the Washakie Basin in Carbon County. That well is now on production,
and a development well is planned later in 1995. This prospect is within 10
miles of a Plains' joint venture with EOG (New Mexico) Inc. to develop the
Almond-Mesaverde formation under 9,207 gross acres. Additionally, Plains plans
to drill its first test on the Golden Gate Unit in June 1995 as a part of its
obligation to earn a 39.9% interest in 29,650 gross acres in the ABeeSey
prospect.
 
  In mid-1994, Plains participated with Foreland Corporation, which acted as
operator, in drilling three development wells in the Eagle Springs Field in
Railroad Valley in Nye County, Nevada that produce oil from the Garrett Ranch
volcanics and the Sheep Pass limestone. A 3-D seismic survey over the field
helped identify potential development locations. All three wells were
successfully completed and produced a combined 8,295 barrels during May 1995.
Upon completion of its expenditure commitment, Plains will have a 40% working
interest in the field and will continue to participate in a development
drilling program that includes drilling four 7,650 foot Eocene Sheep Pass
locations during the 1995 and 1996 calendar years. The first of these wells is
scheduled to begin drilling in June 1995. There are 1,600 gross (640 net) acres
in the field.
 
  In addition to the Eagle Springs development project, Plains joined Foreland
in the North Humboldt prospect, an exploratory oil prospect located in the
northwest part of the Huntington Valley, Elko County, Nevada, where Plains owns
7,693 net lease acres. Gravity mapping and seismic surveys have preliminarily
defined the prospect, and 1995 activity will include the acquisition of trade
seismic data. An initial 6,500 foot Devonian test is expected in the third
quarter of 1995. Plains will pay 66.7% of the cost of the test to earn a 50%
working interest.
 
  Capital spending in 1995 in the Rocky Mountain area is estimated to be
approximately $20.7 million, with approximately $2.7 million scheduled for
exploration, approximately $9.3 million targeted for development drilling and
approximately $8.7 million for secondary and tertiary recovery activities.
 
                                       31
<PAGE>
 
PRODUCTIVE WELLS
 
  Plains had an interest in 1,506 wells as of December 31, 1994 and operated
772 of those wells:
 
<TABLE>
<CAPTION>
                                                              PRODUCTIVE WELLS
                                                             -------------------
                                                             OIL WELLS GAS WELLS
                                                             --------- ---------
                                                             GROSS NET GROSS NET
                                                             ----- --- ----- ---
<S>                                                          <C>   <C> <C>   <C>
Rocky Mountain region......................................   500   71   56   23
Mid-continent region and northeast Colorado................    14   13  575  436
Permian Basin, Texas and Gulf Coast........................   339  208   22   12
                                                              ---  ---  ---  ---
 Total.....................................................   853  292  653  471
                                                              ===  ===  ===  ===
</TABLE>
 
DRILLING ACTIVITY
 
  The following table sets forth Plains' drilling activity for the three months
ended March 31, 1995 and for each of the three years ended December 31, 1994:
 
<TABLE>
<CAPTION>
                                                                  THREE MONTHS
                                      YEAR ENDED DECEMBER 31,         ENDED
                                  -------------------------------   MARCH 31,
                                     1992       1993      1994        1995
                                  ----------- --------- --------- --------------
                                  GROSS  NET  GROSS NET GROSS NET  GROSS   NET
                                  ----- ----- ----- --- ----- --- ------- ------
<S>                               <C>   <C>   <C>   <C> <C>   <C> <C>     <C>
WELLS DRILLED
Development
  Total..........................   56     40   23   16   46   27      10      5
  Successful.....................   50     36   17   15   36   23       8      4
Exploratory
  Total..........................   10      4    9    3   16    3       1     .3
  Successful.....................    1    .33    1   .1    6    1      --     --
Total Wells
  Total..........................   66     44   32   19   62   30      11    5.3
  Successful.....................   51  36.33   18   15   42   24       8      4
</TABLE>
 
RESERVES
 
  The table below sets forth Plains' estimated quantities of proved reserves,
all of which were located in the continental United States, and the present
value of estimated future net revenues from these reserves on a non-escalated
basis discounted by 10% per year as of the end of each of the last three years:
 
<TABLE>
<CAPTION>
                                                                DECEMBER 31,
                                                            --------------------
                                                             1992   1993   1994
                                                            ------ ------ ------
<S>                                                         <C>    <C>    <C>
Estimated Proved Oil Reserves (MMbls).....................    10.0    6.7   11.0
Estimated Proved Natural Gas Reserves (Bcf)...............   315.6  299.5  312.5
Prices as of December 31, for Oil ($/Bbl).................   18.00  12.50  16.00
Prices as of December 31, for Gas ($/Mcf).................    1.84   1.94   1.73
Present Value of Estimated Future Net Revenues (before fu-
 ture income tax expense)
 ($ in millions)..........................................  $226.7 $225.6 $235.1
</TABLE>
 
                                       32
<PAGE>
 
  All of Plains' proved developed reserve quantities of 292.3 Bcf of natural
gas and 7.5 million barrels of oil were estimated at December 31, 1994 by
Netherland, Sewell & Associates, Inc., an independent petroleum engineering
firm. Proved undeveloped reserves were estimated to be 20.1 Bcf and 3.5
million barrels by Plains' petroleum engineers and amounted to approximately
11% of total proved reserve equivalents at December 31, 1994. Proved developed
reserve quantities in prior years were estimated annually by independent
petroleum engineers.
 
  The report of the independent petroleum engineering firm provides estimated
proved developed reserves and future revenues as of December 31, 1994 and
includes an estimate of proved developed reserves established by Plains'
infill drilling in the Kansas Hugoton Field. Reserve estimates for infill
wells are based upon the initial test results and the completion report of
each newly completed well rather than an extrapolation of field-wide data.
However, no proved undeveloped reserves for the Hugoton Field are included in
Plains' estimate.
 
  The reserve quantities are estimates of Plains' net volumes which can be
expected to be recovered commercially at current prices and with existing
conventional equipment and operating methods. Proved developed reserves are
only those reserves expected to be recovered from existing wells. Proved
undeveloped reserves include those reserves expected to be recovered from new
wells and improved recovery projects where additional expenditures are
required.
 
  At December 31, 1994, Plains believes that there are no material estimated
future dismantlement and abandonment costs for its properties. For the purpose
of computing the discounted future net cash flows, estimated future
dismantlement and abandonment costs are assumed to equal the estimated salvage
values of the properties.
 
PRODUCTION, SALES PRICES AND PRODUCTION COSTS
 
  The following table sets forth the average sales price of natural gas and
oil produced and sold and the average production costs per Mcfe for each of
the periods presented.
 
<TABLE>
<CAPTION>
                                                  DECEMBER 31,       MARCH 31,
                                              -------------------- -------------
                                               1992   1993   1994   1994   1995
                                              ------ ------ ------ ------ ------
<S>                                           <C>    <C>    <C>    <C>    <C>
Gas Production (MMcf)........................ 21,654 23,757 23,925  6,142  7,407
Average Sales Price per Mcf.................. $ 1.83 $ 1.94 $ 1.86 $ 2.08 $ 1.67
Oil Production (MBbls).......................  1,039  1,220  1,236    298    405
Average Sales Price per Bbl.................. $18.20 $14.83 $13.91 $11.40 $15.51
Average Production Cost per Mcfe (1)......... $  .91 $  .88 $  .79 $  .83 $  .76
</TABLE>
- --------
(1) Includes lease operations expense, production and property taxes,
    transportation and processing and net profit and natural gas trust
    payments.
 
LEASED ACREAGE
 
  Plains' working interests in leased acreage as of December 31, 1994 are
summarized in the following table:
 
<TABLE>
<CAPTION>
                                              HELD BY PRODUCTION   EXPLORATION
                                              ------------------- --------------
                                                GROSS      NET     GROSS   NET
                                              ------------------- ------- ------
<S>                                           <C>       <C>       <C>     <C>
Colorado....................................     28,902    21,604  35,523 15,092
Kansas......................................    121,616   112,723     640    640
Montana.....................................      3,949     2,539  16,269  8,574
New Mexico..................................     11,456     6,584     600    600
Oklahoma....................................     49,030    37,889   6,571  3,540
Texas.......................................     33,966    21,396  20,216  2,508
Wyoming.....................................     90,425    36,316 110,763 49,440
Other.......................................      5,111     1,497  38,830 19,580
                                              --------- --------- ------- ------
 Total......................................    344,455   240,548 229,412 99,974
                                              ========= ========= ======= ======
</TABLE>
 
                                      33
<PAGE>
 
NET PROFIT AGREEMENTS
 
  Plains produces natural gas in the Oklahoma portion of the Hugoton Field
under a Dry Gas Agreement with Chevron USA, Inc. ("Chevron"). This agreement
allows Plains to expend funds for the operation of the properties (including
the cost of drilling wells) and to recoup the funds so expended from current
production income. Eighty percent of net operating income generated by the
natural gas production (after operational costs are recouped, including the
cost of drilling and equipping wells) is then paid to Chevron. At December 31,
1994, Plains had working interests in 21 Guymon-Hugoton wells and 43 Camrick
wells under the terms of this agreement.
 
  Plains also produces natural gas in the Kansas Hugoton Field under various
agreements similar to the Chevron agreement, except that net operating income
is allocated 15% to Plains and 85% to the other parties. At December 31, 1994,
Plains had working interests in 47 Chase wells and eight Council Grove wells
under such agreements.
 
  Additional or replacement wells drilled on the properties, including wells
drilled under the infill drilling program in the Hugoton Field, would be
operated under the same terms and conditions as existing wells, and would
result in the commencement of the 80/20 or 85/15 net operating income
allocation after the cost of the new wells is recovered.
 
HUGOTON GAS TRUST AGREEMENT
 
  Natural gas rights established in 1955 to some 50,000 partially developed
acres in Finney and Kearny Counties, Kansas were transferred by K N on October
1, 1984 to Plains subject to a natural gas payment of $.06 per Mcf for natural
gas produced from the acreage. Quarterly payments are made by Plains to the
Hugoton Gas Trust, a publicly held trust created in 1955. Payments terminate
when the estimated gross recoverable natural gas reserves decline to 50 Bcf or
less. As of December 31, 1994, the gross proved natural gas reserves
attributable to the leases burdened by this agreement were estimated to be
200.5 Bcf. At December 31, 1994, Plains had working interests in 156 Chase
wells and 42 Council Grove wells which were subject to such payments. Any
additional natural gas wells drilled on this acreage will also be subject to
the $.06 payment per Mcf of natural gas produced.
 
                        POST-MERGER PROFILE AND STRATEGY
 
OIL AND GAS INTERESTS
 
  As a result of the Merger, Barrett will have interests in the Rocky Mountain,
Mid-continent and Gulf Coast areas, including the Piceance, Wind River, Powder
River, Green River, Arkoma, Anadarko, Permian, Gulf Coast and Washakie-Red
Desert Basins. Also following the Merger, Barrett will have interests in an
aggregate of 470,886 gross (273,211 net) developed acres and 440,020 gross
(166,408 net) undeveloped acres.
 
  Based on the March 31, 1995 proved reserves of Barrett and the December 31,
1994 proved reserves of Plains, Barrett will have proved reserves after the
Merger of 609.7 Bcfe (approximately 85% of which will be natural gas). During
the quarter ended March 31, 1995, the daily average production of Barrett and
Plains on a combined basis was 158.1 MMcfe. As of March 31, 1995, after giving
effect to the Merger Barrett and Plains had interests in an aggregate of 2,092
producing natural gas and oil wells.
 
STRATEGY
 
  After the Merger, Barrett intends to continue its strategy of aggressive
growth in reserves and production primarily through generating its own
exploration and development drilling projects. By utilizing the larger cash
flow and other financial resources of the combined entity, Barrett anticipates
that it will be able to develop and exploit more aggressively its and Plains'
existing and future exploration and development projects.
 
  Because of the greater financial strength and size of the combined entity,
Barrett believes that it will be able to operate and compete more effectively
and to take advantage of opportunities that are presented in its current and
post-Merger areas of operations. As a result of having production and reserves
in a larger number of areas, it is anticipated that the combined entity also
will be exposed to a greater number of opportunities to expand its reserve
base.
 
                                       34
<PAGE>
 
  Barrett anticipates that the combined entity will be able to realize
significant reductions in general and administrative expenses from the pre-
Merger combined expenses of Barrett and Plains. It is expected that the
majority of these cost reductions will be through elimination of duplicative
personnel, accounting and other systems, and certain other administrative and
fixed costs of the two pre-Merger companies.
 
  Barrett currently has a line of credit which provides for borrowings up to
$80 million and a borrowing base of $40 million. Plains currently has a $150
million line of credit with an initial borrowing base of $110 million, which
the lender can accelerate and terminate upon a change of control of Plains,
such as upon consummation of the Merger. In connection with the Merger, Barrett
anticipates entering into a single new credit facility. Barrett has had
preliminary discussions with lenders that participate in one or both of the
pre-Merger companies' lines of credit, although no financing commitments have
been requested or made.
 
MANAGEMENT
 
  At the Effective Time, Barrett's Board of Directors will be increased from
nine to 13 members, and the directors of Barrett will elect the Plains
Designees to fill the newly created vacancies. Plains has informed Barrett that
Derrill Cody, William W. Grant, III, William F. Wallace and Harry S. Welch will
be the Plains Designees. All of the Plains Designees currently are directors of
Plains. The terms of all directors of Barrett, including the Plains Designees,
will expire at the next annual meeting of stockholders of Barrett.
 
  In addition, following the Effective Time, William J. Barrett will continue
as Chairman and Chief Executive Officer of Barrett, Paul M. Rady will continue
as President and Chief Operating Officer of Barrett, and William F. Wallace,
currently the President and Chief Operating Officer of Plains, will become Vice
Chairman of Barrett.
 
  The following table sets forth, with respect to each person who is or will be
a director of Barrett at the Effective Time, the person's age and the person's
positions and offices with Barrett. Individual background information
concerning each of such persons follows the table.
 
<TABLE>
<CAPTION>
              NAME               AGE              POSITION WITH BARRETT (7)
              ----               ---              -------------------------
 <C>                             <S>   <C>
 William J. Barrett(1)(4)....... 66    Chairman of the Board of Directors and Chief
                                        Executive Officer
 C. Robert Buford(1)(2)(3)...... 61    Director
 Derrill Cody(6)................ 56    Director
 James M. Fitzgibbons(2)(3)(5).. 60    Director
 Hennie L.J.M. Gieskes(1)(2)(3). 55    Director
 William W. Grant, III(6)....... 63    Director
 J. Frank Keller(4)............. 51    Executive Vice President--Marketing and
                                        Administration, Secretary and a Director
 Paul M. Rady................... 41    President, Chief Operating Officer and a
                                        Director
 A. Ralph Reed.................. 57    Executive Vice President--Operations and a
                                        Director
 James T. Rodgers(2)(3)......... 60    Director
 Philippe S.E. Schreiber(2)(3).. 54    Director
 William F. Wallace(6).......... 55    Vice Chairman of the Board of Directors
 Harry S. Welch(6).............. 71    Director
</TABLE>
- --------
(1) Member of the Executive Committee of the Barrett Board of Directors.
(2) Member of the Audit Committee of the Barrett Board of Directors.
(3) Member of the Compensation Committee of the Barrett Board of Directors.
(4) Mr. Keller and Mr. William J. Barrett are brothers-in-law.
(5) Mr. Fitzgibbons served as a director of Barrett from July 1987 until
    October 1992. He was re-elected to the Barrett Board of Directors in
    January 1994.
(6) Director of Plains.
(7) All officers are elected annually at the first Barrett Board of Directors'
    meeting following the annual meeting of stockholders. Barrett has three
    additional executive officers who are not named in the above table, Joseph
    P. Barrett, Robert W. Howard and Donald H. Stevens. Mr. Joseph Barrett, 41,
    has served as Vice President--Land since March 1995 and as Co-Manager--Land
    since January 1993. Mr. Joseph Barrett is the son of William J. Barrett.
    Mr. Howard, 40, has served as Senior Vice President--Finance and Treasurer
    since March 1992. Mr. Stevens, 42, has served as Vice President--Corporate
    Relations and Capital Markets since August 1992.
 
                                       35
<PAGE>
 
  WILLIAM J. BARRETT has been Chief Executive Officer since December 1983 and
Chairman of the Board of Directors of Barrett since March 1994. Mr. Barrett was
President of Barrett from December 1983 through September 1994. Mr. Barrett has
also been a director of Barrett Fuels Corporation, a wholly owned subsidiary of
Barrett, since its formation in September 1990. From January 1979 to February
1982, Mr. Barrett was an independent oil and gas operator in the western United
States in association with Aeon Energy, a partnership composed of four sole
proprietorships. From 1971 to 1978, Mr. Barrett served as Vice President--
Exploration and a director of Rainbow Resources, Inc., a publicly held
independent oil and gas exploration company that merged with a subsidiary of
the Williams Companies in 1978. Mr. Barrett served as President, Exploration
Manager and Director for B&C Exploration from 1969 until 1971 and was a chief
geologist for Wolf Exploration Company, now known as Inexco Oil Co., from 1967
to 1969. He was an exploration geologist with Pan-American Petroleum
Corporation from 1963 to 1966 and worked as an exploration geologist, a
petroleum geologist and a stratigrapher for El Paso Gas Co. at various times
from 1958 to 1963. Mr. Barrett received a B.S. Degree in Geology and an M.S.
Degree in Geology from Kansas State University in 1956 and 1957, respectively.
 
  C. ROBERT BUFORD has been a director of Barrett since December 1983 and
served as Chairman of the Board of Directors from December 1983 through March
1994. Mr. Buford has been President, Chairman of the Board and controlling
shareholder of Zenith Drilling Corporation ("Zenith"), Wichita, Kansas, since
February 1966. Zenith is engaged in the oil and natural gas business and owns
approximately 5.1 percent of the Barrett Common Stock. Since 1993, Mr. Buford
has served as a director of Encore Energy, Inc., a wholly owned subsidiary of
Zenith engaged in the marketing of natural gas. Mr. Buford is also a member of
the Board of Directors of First Bancorp of Wichita, Kansas, a bank holding
company, and Lonestar Steakhouse & Saloon, Inc., a restaurant company
headquartered in Wichita, Kansas. He received a B.A. Degree in Business
Administration from Oklahoma State University in 1955.
 
  DERRILL CODY has been a director of Plains since 1990. Since January 1990,
Mr. Cody has been an attorney in private practice in Oklahoma City, Oklahoma.
From 1986 to 1990, he was Executive Vice President of Texas Eastern
Corporation, and from 1987 to 1990 he was the Chief Executive Officer of Texas
Eastern Pipeline Company. He has been a director of the General Partner of
TEPPCO Partners, L.P. since January 1990. Mr. Cody received a B.A. Degree in
History from East Central State College in 1960 and an L.L.B. from the
University of Oklahoma in 1964.
 
  JAMES M. FITZGIBBONS has been a director of Barrett since January 1994, and
previously served as a director of Barrett from July 1987 until October 1992.
Since October 1990, Mr. Fitzgibbons has been Chairman and Chief Executive
Officer of Fieldcrest Cannon, Inc., a manufacturer of home furnishing textiles.
From January 1986 until October 1990, Mr. Fitzgibbons was President of Amoskeag
Company in Boston, Massachusetts. Prior to 1986, he was President of Howes
Leather Company, a producer of leather. Mr. Fitzgibbons is also member of the
Board of Directors of Lumber Insurance Company, American Textile Manufacturers
Institute and a Trustee of Laurel Funds, a series of mutual funds. Mr.
Fitzgibbons received an A.B. Degree from Harvard College in 1956.
 
  HENNIE L.J.M. GIESKES has been a director of Barrett since November 1985. Mr.
Gieskes is the Managing Director of Spaarne Compagnie N.V., a Netherlands
company engaged in the investment business. From before 1976 until December
1990, Mr. Gieskes was a Managing Director of Vitol Beheer B.V. ("Vitol"), a
Netherlands trading company engaged primarily in energy-related commodities.
Mr. Gieskes received a law degree from the University of Amsterdam, The
Netherlands, in 1968.
 
  WILLIAM W. GRANT, III has been a director of Plains since 1987. He has been
an advisory director of Colorado National Bankshares, Inc. and Colorado
National Bank since 1993. He was a director of Colorado National Bankshares,
Inc. from 1982 to 1993 and the Chairman of the Board of Colorado National Bank
from 1986 to 1993. He has served as the Chairman of the Board of Colorado
Capital Advisors since 1989.
 
                                       36
<PAGE>
 
Mr. Grant received a B.A. Degree in English from Yale University in 1954 and
attended the Harvard University Graduate School of Business' Advanced
Management Program from 1970 to 1971.
 
  J. FRANK KELLER has been an Executive Vice President, Secretary and a
director of Barrett since December 1983. He also has been the President and a
director of Barrett Fuels Corporation since its formation in September 1990.
Mr. Keller was the President and a co-founder of Myriam Corp., an architectural
design and real estate development firm beginning in 1976, until it was
reorganized as Barrett Energy in February 1982. Mr. Keller graduated from
Kansas State University in 1967 with a B.S. Degree and received an M.B.A.
Degree from Colorado State University in 1992.
 
  PAUL M. RADY was elected President, Chief Operating Officer and a director of
Barrett on September 10, 1994. Prior to his election and appointment, Mr. Rady
served as Executive Vice President--Exploration of Barrett beginning February
1993. From August 1990 until July 1992, Mr. Rady served as Chief Geologist for
Barrett, and from July 1992 until January 1993 he served as Exploration Manager
for Barrett. From July 1980 until August 1990, Mr. Rady served in various
positions with the Denver, Colorado regional office of Amoco Production
Company, the exploration and production subsidiary of Amoco Corporation. Mr.
Rady was a Geologist and Geophysicist for Amoco Production Company. While with
Amoco Production Company, Mr. Rady's areas of responsibility included the Rocky
Mountain Basins, Utah-Wyoming Overthrust Belt, offshore Alaska, Oklahoma,
particularly with respect to the Arkoma Basin, and the New Ventures Group,
which concentrated on the western United States. Mr. Rady received a B.A.
Degree in Geology in 1978 from Western State College of Colorado in Gunnison,
Colorado, and an M.S. Degree in Geology in 1980 from Western Washington
University in Bellingham, Washington.
 
  A. RALPH REED has been an Executive Vice President of Barrett since November
1989 and a director of Barrett since September 1990. From 1986 to 1989, Mr.
Reed was an independent oil and natural gas operator in the mid-continent
region of the United States, including the period from January 1988 to November
1989 when he acted as a consultant to Zenith Drilling Corporation. From 1982 to
1986, Mr. Reed was President and Chief Executive Officer of Cotton Petroleum
Corporation, a wholly owned exploration and production subsidiary of United
Energy Resources, Inc. Prior to joining Cotton Petroleum Corporation in 1980,
Mr. Reed was employed by Amoco Production Company from 1962, holding various
positions including Manager of International Production, Division Production
Manager and Division Engineer. Mr. Reed received a B.S. Degree in Petroleum
Engineering from the University of Oklahoma in 1959 and in 1975 attended the
Executive School at the University of Virginia.
 
  JAMES T. RODGERS has been a director of Barrett since November 1993. Mr.
Rodgers served as the President, Chief Operating Officer and a director of
Anadarko Petroleum Corporation ("Anadarko") from 1986 through 1992. Anadarko is
a Houston-based oil and natural gas exploration and production company. Prior
to 1986, Mr. Rodgers was employed in other capacities by Anadarko and Amoco
Production Company. Mr. Rodgers taught Petroleum Engineering at the University
of Texas in Austin in 1958 and at Texas Tech University in Lubbock from 1958 to
1961. Mr. Rodgers currently serves as a Director of Louis Dreyfus Gas
Corporation and as an Advisory Director for Texas Commerce Bank in Houston. Mr.
Rodgers received a B.S. Degree from Louisiana State University in 1956 and an
M.S. Degree from the University of Texas in 1958.
 
  PHILIPPE S.E. SCHREIBER has been a director of Barrett since November 1985.
Mr. Schreiber is an independent lawyer and business consultant who also is of
counsel to the law firm of Walter, Conston, Alexander & Green, P.C. in New
York, New York. Mr. Schreiber has been affiliated with that law firm as counsel
or partner since August 1985. From 1988 to mid-1992, he also was the Chairman
of the Board and a principal shareholder of HSE, Inc., d/b/a Manhattan Kids
Limited, a privately owned corporation involved in catalogue sales of American
made children's clothing in Europe. From October 1985 through June 1992, Mr.
Schreiber served as a director, and from July 1990 until June 1991 as Managing
Director, of Owl Creek Investments Plc, a publicly traded English oil and
natural gas company. Mr. Schreiber received an A.B. Degree from Columbia
College in 1964 and a J.D. Degree from Columbia University School of Law in
1967.
 
                                       37
<PAGE>
 
  WILLIAM F. WALLACE has been a director of Plains since October 3, 1994. On
that date he also was elected President and Chief Operating Officer of Plains
Petroleum Operating Company, Plains' principal operating subsidiary ("PPOC").
On May 1, 1995, Mr. Wallace was elected to the additional position of President
and Chief Operating Officer of Plains. From 1989 to 1994, he was Regional Vice
President of Texaco Exploration and Production, Inc. From 1988 to 1989 he was
Vice President--Exploration of Texaco USA, Inc. From 1980 to 1988, Mr. Wallace
was Group Vice President, Exploration and Production of CSX Oil and Gas, Inc.,
an independent exploration and production company. From 1964 through 1980, he
held various exploration staff and management positions with Texaco affiliates
in the United States, Trinidad, Venezuela and Colombia. From 1962 through 1964,
he served as a First Lieutenant in the U.S. Army Corps of Engineers. Mr.
Wallace received an A.B. Degree in Geology from Middlebury College in 1961 and
an M.S. Degree in Geology from Stanford University in 1962.
 
  HARRY S. WELCH has been a director of Plains since 1986. Since August 1989,
he has been an attorney in private practice in Houston, Texas. He served as
Vice President and General Counsel of Texas Eastern Corporation from 1988 to
July 1989. Mr. Welch received a B.B.A. Degree and an L.L.B. Degree from the
University of Texas in 1947 and 1949, respectively.
 
                              THE SPECIAL MEETINGS
 
MATTERS TO BE CONSIDERED AT THE SPECIAL MEETINGS
 
  BARRETT SPECIAL MEETING. At the Barrett Special Meeting, holders of shares of
Barrett Common Stock will consider and vote upon proposals to approve the
Charter Amendment and the Stock Issuance. Holders of shares of Barrett Stock
entitled to vote also will consider and vote upon any other matter that may
properly come before the Barrett Special Meeting or any adjournments or
postponements thereof.
 
  THE BOARD OF DIRECTORS OF BARRETT HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT, THE MERGER AND THE OTHER TRANSACTIONS CONTEMPLATED THEREBY,
INCLUDING THE CHARTER AMENDMENT AND THE STOCK ISSUANCE, AND RECOMMENDS A VOTE
FOR THE APPROVAL OF THE CHARTER AMENDMENT AND THE STOCK ISSUANCE. See "THE
MERGER--Recommendations of the Boards of Directors; Reasons for the Merger."
 
  PLAINS SPECIAL MEETING. At the Plains Special Meeting, holders of shares of
Plains Common Stock will consider and vote upon a proposal to approve and adopt
the Merger Agreement and the Merger. Holders of shares of Plains Common Stock
entitled to vote also will consider and vote upon any other matter that may
properly come before the Plains Special Meeting or any adjournments or
postponements thereof.
 
  THE BOARD OF DIRECTORS OF PLAINS HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT, THE MERGER AND THE OTHER TRANSACTIONS CONTEMPLATED THEREBY, AND
RECOMMENDS A VOTE FOR THE APPROVAL AND ADOPTION OF THE MERGER AGREEMENT AND THE
MERGER. See "THE MERGER--Recommendations of the Boards of Directors; Reasons
for the Merger."
 
  Subject to certain provisions described herein with respect to shares owned
by Plains, Barrett and their respective subsidiaries, in the Merger each issued
and outstanding share of Plains Common Stock, together with its associated
Right, will be converted into 1.3 validly issued, fully paid and nonassessable
shares of Barrett Common Stock. Cash will be paid in lieu of fractional shares
of Barrett Common Stock. See "THE MERGER--Merger Consideration" and "--
Fractional Shares."
 
VOTES REQUIRED
 
  BARRETT. The approval of the Charter Amendment requires the affirmative vote
of a majority of the outstanding shares of Barrett Common Stock. The approval
of the Stock Issuance requires the affirmative vote of a majority of the votes
cast on the proposal, provided that the total votes cast on the proposal
represent a majority of the outstanding shares of Barrett Common Stock entitled
to vote thereon.
 
                                       38
<PAGE>
 
  Abstentions will be counted as shares present for purposes of determining the
presence of a quorum on all matters. See "--Record Dates; Stock Entitled to
Vote; Quorum." Abstentions will have the effect of votes against the approval
of the Charter Amendment and the Stock Issuance. In addition, brokers who hold
shares of Barrett Common Stock as nominees will not have discretionary
authority to vote such shares in the absence of instructions from the
beneficial owners thereof. Votes which are not cast for this reason ("broker
non-votes") also will have the effect of a vote against the Charter Amendment.
Broker non-votes with respect to the Stock Issuance will not have the effect of
a vote for or against the matter.
 
  As of June 13, 1995, directors and executive officers of Barrett and their
affiliates were beneficial owners of an aggregate of approximately 2,133,693
shares (approximately 17.6%) of the outstanding shares of Barrett Common Stock
(including 138,797 shares subject to options exercisable within 60 days). The
directors of Barrett who are also stockholders of Barrett have agreed to vote
their shares of Barrett Common Stock in favor of the matters submitted to
stockholders of Barrett at the Barrett Special Meeting or any adjournments or
postponements thereof. As of June 13, 1995, the directors of Barrett
beneficially owned 1,983,183 shares of Barrett Common Stock (excluding shares
subject to options).
 
  PLAINS. The Merger Agreement must be approved and adopted by the affirmative
vote of a majority of the outstanding shares of Plains Common Stock entitled to
vote thereon.
 
  Abstentions will be counted as shares present for purposes of determining the
presence of a quorum on all matters. See "--Record Dates; Stock Entitled to
Vote; Quorum." Abstentions will have the effect of votes against the approval
and adoption of the Merger Agreement, the Merger and the other transactions
contemplated by the Merger Agreement. In addition, brokers who hold shares of
Plains Common Stock as nominees will not have discretionary authority to vote
such shares in the absence of instructions from the beneficial owners thereof.
Broker non-votes also will have the effect of a vote against the proposal.
 
  As of June 13, 1995, directors and executive officers of Plains and their
affiliates were beneficial owners of an aggregate of 268,267 shares
(approximately 2.7%) of the outstanding shares of Plains Common Stock
(including 219,073 shares subject to options exercisable within 60 days). The
directors of Plains who are also stockholders of Plains have agreed to vote
their shares of Plains Common Stock in favor of the matters submitted to
stockholders of Plains at the Plains Special Meeting or any adjournments or
postponements thereof. As of June 13, 1995, the directors of Plains
beneficially owned 22,774 shares of Plains Common Stock (excluding shares
subject to options).
 
VOTING OF PROXIES
 
  Shares represented by all properly executed proxies received in time for the
Special Meetings and which have not been revoked will be voted at such meetings
in the manner specified by the holders thereof. PROXIES WHICH DO NOT CONTAIN AN
INSTRUCTION TO VOTE FOR OR AGAINST OR TO ABSTAIN FROM VOTING ON A PARTICULAR
MATTER DESCRIBED IN THE PROXY WILL BE VOTED IN FAVOR OF SUCH MATTER.
 
  It is not expected that any matter other than those referred to herein will
be brought before either of the Special Meetings. If, however, other matters
are properly presented, the persons named as proxies will vote in accordance
with their judgment with respect to such matters, unless authority to do so is
withheld in the proxy.
 
REVOCABILITY OF PROXIES
 
  The grant of a proxy on the enclosed Barrett or Plains form of proxy does not
preclude a stockholder from voting in person. A stockholder may revoke a proxy
at any time prior to its exercise by submitting a later dated proxy with
respect to the same shares, by filing with the Secretary of Barrett (in the
case of a Barrett stockholder) or the Secretary of Plains (in the case of a
Plains stockholder) a duly executed revocation, or by voting in person at the
meeting. Attendance at the relevant Special Meeting will not in and of itself
constitute a revocation of a proxy.
 
                                       39
<PAGE>
 
RECORD DATES; STOCK ENTITLED TO VOTE; QUORUM
 
  BARRETT. Only holders of record of Barrett Common Stock at the close of
business on June 13, 1995 (the "Barrett Record Date") will be entitled to
receive notice of and to vote at the Barrett Special Meeting. On the Barrett
Record Date, Barrett had outstanding     shares of Barrett Common Stock. The
holders of Barrett Common Stock are entitled to one vote per share on each
matter submitted to a vote at the Barrett Special Meeting. For purposes of the
Barrett stockholder vote with respect to the approval of the Charter Amendment,
a majority of the outstanding shares of Barrett Common Stock entitled to vote
must be present in person or by proxy at the Barrett Special Meeting in order
for a quorum to be present. For purposes of the Barrett stockholder vote with
respect to the approval of the Stock Issuance, the holders of a majority of the
shares of Barrett Common Stock entitled to vote must be present in person or by
proxy at the Barrett Special Meeting in order for a quorum to be present.
Shares of Barrett Common Stock represented by proxies which are marked
"abstain" or which are not marked as to any particular matter or matters will
be counted as shares present for purposes of determining the presence of a
quorum on all matters. Proxies relating to "street name" shares that are voted
by brokers will be counted as shares present for purposes of determining the
presence of a quorum on all matters, but will not be treated as shares having
voted at the Barrett Special Meeting as to any proposal as to which authority
to vote is withheld by the broker.
 
  In the event a quorum is not present in person or by proxy at the Barrett
Special Meeting, the Barrett Special Meeting is expected to be adjourned or
postponed.
 
  PLAINS. Only holders of record of Plains Common Stock at the close of
business on June 13, 1995 (the "Plains Record Date"), will be entitled to
receive notice of and to vote at the Plains Special Meeting. On the Plains
Record Date, Plains had outstanding     shares of Plains Common Stock. The
holders of Plains Common Stock are entitled to one vote per share on each
matter submitted to a vote at the Plains Special Meeting. The holders of a
majority of the outstanding shares of Plains Common Stock entitled to vote must
be present in person or by proxy at the Plains Special Meeting in order for a
quorum to be present. Shares of Plains Common Stock represented by proxies
which are marked "abstain" or which are not marked as to any particular matter
or matters will be counted as shares present for purposes of determining the
presence of a quorum on all matters. Proxies relating to "street name" shares
that are voted by brokers will be counted as shares present for purposes of
determining the presence of a quorum on all matters, but will not be treated as
shares having voted at the Plains Special Meeting as to any proposal as to
which authority to vote is withheld by the broker.
 
  In the event a quorum is not present in person or by proxy at the Plains
Special Meeting, the Plains Special Meeting is expected to be adjourned or
postponed.
 
APPRAISAL RIGHTS
 
  Holders of Plains Common Stock who vote against the Merger will not be
entitled to appraisal rights under the DGCL if the Merger is consummated. The
DGCL generally entitles a stockholder to exercise appraisal rights upon a
merger or consolidation of the corporation effected pursuant to the DGCL if the
holder complies with the requirements of Section 262 of the DGCL. Appraisal
rights are available under Section 262 of the DGCL if holders of shares in a
constituent company, which shares are listed on a national securities exchange
(as the shares of Plains Common Stock are), are required by the terms of the
merger to accept consideration other than shares of stock of the surviving
corporation, shares of stock of any corporation listed on a national securities
exchange, designated as a national market system security by the National
Association of Securities Dealers, Inc. or held of record by more than 2,000
stockholders, or cash in lieu of fractional shares. Holders of Plains Common
Stock will receive only Barrett Common Stock, which is listed on the NYSE, and
cash in lieu of fractional shares under the terms of the Merger Agreement.
Consequently, holders of Plains Common Stock will not be entitled to appraisal
rights under the DGCL.
 
 
                                       40
<PAGE>
 
  At the Barrett Special Meeting, holders of shares of Barrett Common Stock
will consider and vote upon proposals to approve the Charter Amendment and the
Stock Issuance. Holders of Barrett Common Stock will not be entitled to
appraisal rights under the DGCL.
 
SOLICITATION OF PROXIES
 
  Subject to the Merger Agreement, each of Barrett and Plains will bear the
cost of the solicitation of proxies from its own stockholders, except that
Barrett and Plains will share equally the cost of printing and mailing this
Joint Proxy Statement/Prospectus. In addition to solicitation by mail, the
directors, officers and employees of each corporation and its subsidiaries may
solicit proxies from stockholders of such corporation by telephone or telegram
or in person. Such directors, officers and employees will not be additionally
compensated for such solicitation but may be reimbursed for out-of-pocket
expenses in connection therewith. Arrangements also will be made with brokerage
houses and other custodians, nominees and fiduciaries for the forwarding of
solicitation material to the beneficial owners of shares held of record by such
persons, and Barrett and Plains will reimburse such custodians, nominees and
fiduciaries for their reasonable out-of-pocket expenses in connection
therewith.
 
  Corporate Investor Communications Inc. will assist in the solicitation of
proxies by Barrett for fees of $3,500, plus reimbursement of a maximum of
$3,000 of out-of-pocket expenses. D.F. King & Co., Inc. will assist in the
solicitation of proxies by Plains for fees of $7,000, plus reimbursement of
reasonable out-of-pocket expenses.
 
  HOLDERS OF BARRETT COMMON STOCK AND PLAINS COMMON STOCK SHOULD NOT SEND STOCK
CERTIFICATES WITH THEIR PROXY CARDS.
 
                                   THE MERGER
 
  The description of the Merger and the Merger Agreement contained in this
Joint Proxy Statement/Prospectus is qualified in its entirety by reference to
the Merger Agreement, a copy of which is included as Annex I to this Joint
Proxy Statement/Prospectus and is incorporated herein by reference.
 
GENERAL
 
  Barrett, Sub and Plains have entered into the Merger Agreement, which
provides that, subject to the satisfaction or waiver of the conditions set
forth therein (see "--Conditions to the Consummation of the Merger"), Sub will
be merged with and into Plains, and Plains will be the Surviving Corporation
and a wholly owned subsidiary of Barrett. As soon as practicable after the
satisfaction or waiver (where permisible) of the conditions under the Merger
Agreement, the Certificate of Merger will be filed with the Secretary of State
of the State of Delaware, and the time of such filing will be the Effective
Time unless otherwise provided in the Certificate of Merger.
 
BACKGROUND OF THE MERGER
 
  In mid-November 1993, an independent oil company ("Company One") contacted
Mr. James A. Miller, then the President and Chief Executive Officer of Plains,
to discuss a possible strategic merger with Plains. On December 7, 1993, Mr.
Miller reviewed with the Board of Directors of Plains the preliminary contact
with Company One. Following such meeting, the Plains Board of Directors engaged
Goldman Sachs as its financial advisor to assist it in considering a broad
range of strategic options, including the consideration of a strategic merger.
The Plains Board convened a special meeting on December 21, 1993, at which it
reviewed with its financial advisor its existing strategy, as well as the
alternatives of pursuing a major acquisition of an oil and natural gas company
or a major oil and natural gas producing property, a strategic merger with an
oil and natural gas company, or the sale of Plains. At the meeting, after
considering, among other things, the presentation of Goldman Sachs, the Plains
Board determined to pursue its existing growth strategy but also to consider
strategic merger opportunities. In that regard, the Plains Board authorized
management to investigate further the possibility of a stock-for-stock merger
with Company One.
 
                                       41
<PAGE>
 
  In late December 1993, Mr. William J. Barrett, then the President and Chief
Executive Officer of Barrett, contacted Mr. Miller and proposed a meeting to
discuss a possible business combination between Barrett and Plains. On December
30, 1993, Mr. Barrett, Mr. C. Robert Buford, then Barrett's Chairman of the
Board, and Mr. Miller met to explore the possibility of a stock-for-stock
merger and exchanged publicly available information regarding their respective
companies.
 
  In January 1994, Plains and Company One each executed confidentiality and
standstill agreements. During the months of January and February 1994, Plains
and Company One conducted due diligence reviews of one another, although
specific merger proposals were not discussed. In March 1994, Plains and Company
One mutually agreed that there was no basis to continue further discussions. At
the same time, informal and sporadic conversations took place between Barrett
and Plains until April 1994.
 
  On April 11, 1994, the Plains Board met with its legal and financial advisors
to continue the Plains Board's review of strategic alternatives.
 
  On April 14, 1994, Mr. Barrett delivered a letter to Mr. Miller stating that
the Board of Directors of Barrett had decided that a merger with Plains was not
in the best interests of Barrett's stockholders at that time because Barrett
was planning to develop a large amount of low risk gas reserves during the next
several years and, until such development, Barrett's stock price probably would
not adequately reflect the value of those properties. On April 14, 1994, the
closing price of Barrett Common Stock was $13.375 per share. Discussions
between the two companies thereafter concluded.
 
  On July 25, 1994, Mr. Jon Brumley, the Chairman of the Board of Cross Timbers
Oil Company ("Cross Timbers") telephoned Mr. Miller to inform him that Cross
Timbers beneficially owned approximately 4.9% of Plains' outstanding shares
(which number included shares of Plains Common Stock held in portfolio accounts
managed by a director of Cross Timbers). On August 2, 1994, at Mr. Brumley's
suggestion, Mr. Miller and Mr. Robert M. Danos, then the President of Plains
Petroleum Operating Company (a wholly owned subsidiary of Plains), met with Mr.
Brumley and Mr. Bob R. Simpson, the Vice Chairman of the Board and Chief
Executive Officer of Cross Timbers. At such meeting, the representatives of
Cross Timbers suggested a possible merger between Cross Timbers and Plains,
although they did not present any specific proposals.
 
  On August 11, 1994, the Plains Board met and discussed, among other things,
the August 2nd meeting with Cross Timbers. On August 15, 1994, Plains retained
Batchelder & Partners, Inc. ("Batchelder") to join with Goldman Sachs in
advising Plains.
 
  On August 31, 1994, representatives of another independent oil and natural
gas company ("Company Two") contacted Mr. Danos and an outside director of
Plains to inform each of them that it had accumulated a significant number of
shares of Plains Common Stock.
 
  At its regular meeting held on September 8, 1994, the Plains Board reviewed
with its legal and financial advisors the above-mentioned inquiries concerning
possible strategic alliances with Plains or the sale of Plains, Plains'
operations and financial performance and its strategic alternatives. The Plains
Board determined that Plains should continue to pursue its independent growth
strategy through acquisitions, exploration and strong operating management, and
that Plains was not for sale.
 
  On September 19, 1994, Cross Timbers filed with the Commission a Schedule 13D
indicating that, as of such date, Cross Timbers beneficially owned 550,000
shares of Plains Common Stock (which number did not include the shares in
portfolio accounts managed by a director of Cross Timbers), or approximately
5.6% of the outstanding shares. In the Schedule 13D, Cross Timbers stated that
its ownership of Plains Common Stock could serve as a basis for a possible
attempt by Cross Timbers to acquire control of Plains if Cross Timbers should
decide to do so. Cross Timbers also stated that it might seek representation on
Plains' Board of Directors in order to influence management to take specific
steps to enhance stockholder value.
 
   On October 5, 1994, Batchelder met with representatives of Company Two,
during which meeting such representatives proposed a possible framework for a
possible combination of Plains and Company Two that would result in the Plains
stockholders owning more than 50% of the combined enterprise. No specific terms
were discussed.
 
 
                                       42
<PAGE>
 
  On October 19, 1994, Goldman Sachs and Plains entered into a new engagement
letter providing for the engagement of Goldman Sachs as financial advisor to
Plains with respect to an acquisition by Cross Timbers or any tender offer,
merger or other similar transaction with any other person, rather than with
respect to general advisory services.
 
  At the Plains Board's regular meeting held on October 19, 1994, the Plains
Board of Directors, together with its legal and financial advisors, reviewed
the Cross Timbers Schedule 13D. The Plains Board also engaged in a
comprehensive review of its strategic options. Included in this review was the
combined presentation of Goldman Sachs and Batchelder which, among other
things, provided an overview of the merger market for oil and natural gas
companies and outlined various strategic options available to Plains, including
pursuing an independent growth strategy, a strategic merger with an oil and
natural gas company and the sale of Plains. The Plains Board of Directors
determined that Plains should continue to pursue aggressively its growth
strategy. However, in light of Cross Timbers' Schedule 13D filing, the Plains
Board of Directors decided that Plains should engage in a thorough study of the
alternative strategy of a possible stock-for-stock merger with one of a group
of widely held public companies in the energy industry. As part of this study,
the Plains Board of Directors authorized Goldman Sachs and Batchelder to seek
preliminary indications of interest from a group of possible merger partners
believed to present potential synergistic or strategic value. The Plains Board
of Directors concluded that if the study failed to yield a superior alternative
to its existing growth strategy by year-end, Plains would continue to pursue
such existing growth strategy. In addition, the Plains Board of Directors
amended its stockholders rights plan to lower the threshold for a person to
become an "Acquiring Person," and thereby trigger a distribution of the Rights,
to 15% and to make certain other changes. The Plains Board determined that such
amendments were necessary to preserve the Board's ability to control the study
process and to pursue business combinations in the best interests of Plains'
stockholders. A press release announcing the Board's actions was issued on
October 20, 1994.
 
  On October 21, 1994, Cross Timbers filed an amendment to its Schedule 13D
indicating that, as of October 20, 1994, Cross Timbers beneficially owned
644,500 shares of Plains Common Stock (which number did not include the shares
in portfolio accounts managed by a director of Cross Timbers), or approximately
6.6% of the outstanding shares. The amended Schedule 13D also stated that Cross
Timbers was reconsidering all of its own alternatives in light of Plains'
announced decision to study strategic alternatives.
 
  On October 26, 1994, the Plains Board held a special meeting to review with
its financial advisors the inquiries received in light of the public disclosure
of the Plains Board's October 19th decision. The Plains Board again reviewed
the status of its strategic study at its November 16 regular meeting. Plains'
financial advisors delivered to the Plains Board a presentation that, among
other things, provided an updated overview of the merger market for oil and
natural gas companies, and summarized certain publicly available information on
four study participants that had executed confidentiality and standstill
agreements and that were reviewing confidential data prepared by Plains with
the assistance of its financial advisors.
 
  During October and November 1994, Plains' financial advisors solicited a
total of eight public companies in the energy industry, a total of four of
which signed confidentiality and standstill agreements and were invited to
conduct due diligence investigations of Plains and to submit preliminary
indications of interest for a stock-for-stock combination. Another company,
which was not originally solicited, also signed a confidentiality and
standstill agreement, conducted due diligence and was invited to submit a
preliminary indication of interest for a stock-for-stock combination. Cross
Timbers and Company Two were among those invited to participate in this
process. Cross Timbers declined to do so because it was unwilling to execute
the confidentiality and standstill agreement in the form which had been
executed by the other participants. Specifically, Cross Timbers objected to
being limited to submitting a stock-for-stock proposal. Company Two declined to
participate because it did not wish to restrict the actions it might take with
respect to Plains Common Stock due to its access to confidential Plains'
information. All of the study participants were requested to conclude their due
diligence reviews and submit preliminary, non-binding proposals before December
12, 1994.
 
  On December 14, 1994, Company Two delivered a letter to Plains proposing a
merger in which holders of Plains Common Stock would receive a combination of
cash and common stock that Company Two claimed
 
                                       43
<PAGE>
 
to be worth $27 per share of Plains Common Stock. In its preliminary proposal,
Company Two stated the cash component of its proposal was $14.25 for each
share of Plains Common Stock. It attributed in its preliminary proposal a
value of $12.00 per share to its common stock and, therefore, indicated it
would exchange 1.0625 shares of its common stock for each share of Plains
Common Stock. (However, on December 14, 1994, the closing price of Company
Two's common stock was $8.625 per share.) In addition, the Company Two
proposal was preliminary and non-binding and subject to, among other things,
due diligence and board approval. On December 14, 1994, the closing price of
Plains Common Stock was $24 per share.
 
  During the Plains Board's regular meeting on December 15, 1994, the Plains
Board reviewed with its financial advisors the two preliminary indications of
interest that had been received from the five remaining study participants as
well as the letter from Company Two. Both of the proposals from the study
participants were preliminary and nonbinding and subject to due diligence,
regulatory approvals, board approval and other conditions. One of these study
participants, a large capitalization independent oil and natural gas company
("Participant One"), proposed a stock-for-stock merger agreement with a fixed
exchange ratio. Based on the closing price of Participant One's common stock
on December 15, 1994, this preliminary proposal represented an offer of
approximately $23 per share of Plains Common Stock. The other study
participant submitting a preliminary proposal, a medium capitalization
independent oil and natural gas company ("Participant Two"), proposed a
consolidation of Plains and Participant Two into a newly formed holding
company. Based on numerous assumptions by Participant Two (not necessarily
agreed to by Plains' Management), including, among others, the belief that the
newly formed holding company would trade at a valuation materially higher than
the sum of the two companies, this proposed consolidation transaction, in the
view of Participant Two, indicated an implied price of approximately $27 per
share of Plains Common Stock. However, based on the trading price for the
stock of Participant Two then prevailing and the proposed ratio of ownership
of the newly formed holding company, this proposed consolidation indicated an
implied price of approximately $20 per share of Plains Common Stock. On
December 15, 1994, the closing price of Plains Common Stock was $23.875 per
share.
 
  At the December 15th meeting, Plains' financial advisors, among other
things, presented an update of the merger market for oil and natural gas
companies, reviewed with the Plains Board of Directors the preliminary
indications of interest received to date, and reviewed the options available
to Plains that they had previously reviewed with the Board. The Plains Board,
among other things, reviewed with its financial advisors the fact that
declining natural gas prices had adversely affected the stock prices of
independent exploration and production companies, hampering their ability to
consummate stock-for-stock merger transactions. After evaluating the proposals
of Participant One and Participant Two with Plains' financial advisors, the
Plains Board determined to pursue further discussions with both companies to
explore further the values that might be realized in transactions with such
parties. With respect to the proposal from Company Two, the Plains Board
reaffirmed its decision to pursue its study of stock-for-stock transactions
exclusively and, accordingly, reaffirmed that it was not soliciting any offers
involving a sale of Plains. Mr. Miller delivered a letter dated December 15,
1994 to Company Two stating the Plains Board's decision. The Board of
Directors of Plains on December 19, 1994 publicly announced that Plains was
continuing discussions with a narrowed field of possible merger partners and
that Plains hoped to reach some study conclusions by late January.
 
  In January and February 1995, three additional companies indicated their
respective interest in a stock-for-stock merger with Plains, and each executed
a confidentiality and standstill agreement and commenced due diligence. During
January, Plains and Participant Two exchanged additional information about
their respective companies but were unable to agree on an acceptable valuation
of the two companies for the proposed consolidation transaction. Participant
Two eventually submitted a proposal to merge with Plains for a consideration
of approximately $15 per share, consisting of cash and securities. The
Participant Two proposal was preliminary and nonbinding and subject to certain
adjustments, negotiation of a definitive agreement and other conditions. On
the date of such preliminary proposal, the closing price of the Plains Common
Stock was $21.75 per share. Plains rejected this proposal because it was
inconsistent with the Plains Board's study of stock-for-stock merger
alternatives and represented a price below the market price of Plains Common
Stock. On
 
                                      44
<PAGE>
 
January 27, 1995, at the direction of the Plains Board, Plains' financial
advisors informed Participant One that, after Plains' due diligence
investigation of Participant One, Plains had declined to pursue further
discussions regarding their merger proposal.
 
  On February 2, 1995, Plains announced that, due to industry-wide
developments, Plains was unable to complete its study within its previously
anticipated timetable but that a decision was expected by the end of February.
The Board reiterated that, if the study failed to produce a superior
alternative to its existing growth strategy, Plains would continue such
strategy.
 
  On February 8, 1995, in light of the conversations which had taken place a
year earlier, Mr. Miller contacted Mr. Barrett to suggest that Barrett
participate in Plains' strategic study. After consultation with the Barrett
Board of Directors, Mr. Barrett telephoned Mr. Miller and indicated that
Barrett would enter the study process.
 
  On February 10, 1995, Plains received from WTW Properties, Inc., a wholly
owned subsidiary of Cross Timbers, a written notice stating that WTW
Properties intended to nominate two officers of Cross Timbers for election as
directors of Plains at Plains' 1995 annual meeting of stockholders.
 
  On February 16, 1995, the Plains Board met with its legal and financial
advisors to discuss, among other things, the status of the strategic study and
the proposed nominations by Cross Timbers. In addition, the Plains Board was
informed of the contacts with Barrett and discussed with Plains' financial
advisors financial information regarding Barrett.
 
  On February 17 and 20, 1995, Plains and Barrett, respectively, executed
confidentiality and standstill agreements and commenced extensive due
diligence investigations of each other. These investigations included meetings
of representatives of the two parties on February 20 and 21, 1995 at Plains'
office for an initial asset review and review of preliminary information
concerning Plains. Also, on February 20, 1995, the Board of Directors of
Barrett met to discuss the status of the discussions with Plains concerning a
potential business combination and to discuss the merits of going forward with
further evaluation of Plains. The Barrett Board of Directors approved going
forward with discussions with Plains and with the engagement of Petrie Parkman
to assist Barrett in evaluating Plains and in structuring a potential business
combination. On February 21, 1995, Barrett engaged Petrie Parkman as its
financial advisor. On February 23 and 24, 1995, representatives of Plains
visited Barrett's offices for an initial review of the assets and operations
of Barrett.
 
  On February 26, 1995, the Barrett Board of Directors met to discuss the
potential business combination with Plains and to review a preliminary
analysis of the business combination. Management of Barrett and
representatives of Petrie Parkman provided their analyses of the proposed
business combination and various matters in connection with proposed
structures for the combination. Based on the information presented to the
Barrett Board of Directors, the Barrett Board of Directors determined to
pursue discussions with Plains based on a framework suggested by management
and Petrie Parkman, including a stock-for-stock exchange of Barrett Common
Stock for each share of Plains Common Stock. On February 27, 1995,
representatives of Barrett and Plains discussed Barrett's proposal for the
business combination, which provided for a strategic merger in which holders
of Plains Common Stock would receive 1.2 shares of Barrett Common Stock for
each share of Plains Common Stock held by them. Based upon the closing price
of $18.75 per share of Barrett Common Stock on February 27, 1995, this Barrett
proposal valued Plains at approximately $22.50 per share.
 
  At a dinner meeting with the Plains Board on February 27, 1995, Mr. Miller
informed the Plains Board of Directors of the Barrett proposal and that
management would not recommend to the Plains Board the acceptance of the
proposed exchange ratio at the then market price of Barrett Common Stock. On
February 28, the Plains Board met with its legal and financial advisors to
discuss, among other things, the Barrett proposal. None of the three
additional participants that joined the study in January 1995 ultimately
submitted a proposal to Plains. The Plains Board determined that the
indications of interest and preliminary proposals received by Plains reflected
the depressed market for common stock of public companies in the energy
industry. In addition, although Plains had engaged in thorough and detailed
discussions with a number of merger partners, the Plains Board concluded that
no proposal had developed which the Plains Board was prepared to recommend to
Plains' stockholders. On February 28, 1995, Plains informed Barrett that it
was not interested in continuing to pursue a transaction based on the
negotiations to date.
 
 
                                      45
<PAGE>
 
  At its February 28 meeting, after considering the presentations of Goldman
Sachs and Batchelder, the Plains Board of Directors also determined that
Plains' stockholders could benefit from a transaction and that companies in
the energy industry recognize the value of Plains, particularly its long-lived
natural gas reserves and strong balance sheet, and would be interested in
pursuing a transaction with Plains. Accordingly, the Board of Directors of
Plains authorized Goldman Sachs and Batchelder to seek indications of interest
from a broader group of companies and also for a broader range of
transactions, including transactions involving an acquisition of Plains for
cash or a combination of cash and securities. Plains issued a press release on
March 1, 1995 disclosing the Plains Board's determinations and further
announcing that Plains' annual meeting of stockholders originally scheduled
for April 13, 1995 had been postponed, pending the results of this expanded
study. Plains also reaffirmed that if this expanded study process did not
yield a proposal in the best interests of the stockholders, Plains would
continue to pursue its independent strategy of growth through acquisitions,
exploration and development.
 
  Beginning on March 1, 1995, Goldman Sachs and Batchelder solicited
indications of interest from 75 companies in the energy industry believed to
be financially capable of consummating a transaction with Plains. Barrett,
Cross Timbers and Company Two were among the companies contacted for this
expanded study. Barrett's financial advisor indicated to Plains' financial
advisor that Barrett was reluctant to enter into the expanded study at that
time. Neither Cross Timbers nor Company Two participated in the process. After
initial inquiries, 47 companies were eventually asked to execute a
confidentiality and standstill agreement. Twenty-two of these companies
executed the agreement and received extensive and detailed confidential
information regarding Plains. In connection with this expanded study, the
participants were requested to submit their non-binding, preliminary
indications of interest in a transaction with Plains no later than April 28,
1995. The participants were informed that visits to Plains' "data room" for
due diligence were scheduled to begin on or about May 8 for those companies
invited by Plains to do so. The data room visits were designed to enable
participants to confirm the information contained in the detailed confidential
materials previously supplied to them.
 
  On April 11, 1995, in light of the two prior rounds of discussions, Mr.
Miller attempted to reach Mr. Barrett by telephone to discuss Barrett's
participation in the expanded study. Mr. Barrett returned Mr. Miller's call on
April 12, and later that day, Mr. Barrett, Mr. Buford and Barrett's financial
advisor met with Mr. Miller and Mr. William F. Wallace, the new President of
Plains Petroleum Operating Company. At such meeting, the Barrett
representatives discussed Plains' expanded study but indicated that they had
not yet made any decisions regarding their participation. On April 13,
Barrett's representatives requested and received a copy of the confidential
materials that had been delivered to the other expanded study participants.
Barrett also executed a new confidentiality and standstill agreement. On April
13, 1995, management and certain directors of Barrett met with representatives
of Petrie Parkman to discuss the potential structure and terms of a possible
business combination with Plains. Based on this discussion, Barrett elected to
continue its due diligence and develop a proposal for a transaction with
Plains.
 
  On April 18, 1995, Cross Timbers filed a further amendment to its Schedule
13D stating that, pending the completion of Cross Timbers' acquisition of
certain natural gas producing properties, Cross Timbers did not currently
intend to pursue a business combination with Plains. The amended Schedule 13D
stated that Cross Timbers accordingly did not currently plan to enter into a
confidentiality agreement with Plains or to seek confidential financial or
operating information from Plains which might be available as part of Plains'
expanded strategic study.
 
  On April 19, 1995, the Board of Directors of Barrett met with Barrett
management and representatives of Petrie Parkman to discuss the status of its
due diligence review of Plains. After again reviewing relevant information
concerning a potential business combination, Barrett determined to continue to
pursue a business combination with Plains, and the Barrett Board of Directors
authorized an offer to exchange up to 1.3 shares of Barrett Common Stock for
each share of Plains Common Stock. This offer, which represented a higher
ratio than Barrett had been willing to offer in the prior negotiations, was
made orally on April 19. The offer was conditioned upon the absence of any
price protection mechanisms ("collars") or termination rights based solely on
a decline in the price of Barrett Common Stock ("walkaways"). Barrett also
requested as a condition to further discussion an opportunity to negotiate a
stock-for-stock merger with Plains prior to the April 28th due date for the
preliminary indications of interest. Plains agreed to engage in negotiations
but
 
                                      46
<PAGE>
 
refused to terminate the solicitation of preliminary indications of interest
from other parties or to delay the April 28th due date. Based upon the closing
price of Barrett Common Stock of $23.25 per share on April 19, 1995, the
Barrett proposal valued Plains at $30.23 per share.
 
  On April 20, 1995, Plains provided Barrett with a form of agreement and plan
of merger that had been prepared by Plains' counsel in connection with earlier
merger discussions with other potential merger partners and requested that
Barrett provide Plains with a detailed proposal that included all of its
material terms and conditions. The form of the draft agreement, which had
previously been reviewed by the Plains Board, contemplated the possibility of
collars and included a walkaway right (despite Barrett's earlier insistence to
the contrary) and a right to terminate the agreement to accept a superior
proposal without any payment of fees or expenses. Throughout this period, the
expanded study process involving 21 other participants continued.
 
  On April 21, 1995, representatives of Plains visited Barrett's offices to
undertake an updated review of Barrett's assets and operations and to discuss
various aspects of the proposed business combination.
 
  On April 24, 1995, Barrett delivered to Plains a detailed proposal in the
form of a markup of Plains' draft merger agreement. The April 24th proposal
included, among other things, the 1.3 exchange ratio with no collars or
walkaway rights, a termination fee that would be triggered upon numerous events
and the inclusion of two Plains directors on the Board of Directors of the
combined company.
 
  At a special meeting of the Plains Board of Directors held on April 26, the
Plains Board reviewed Barrett's proposal with Plains' legal and financial
advisors. Goldman Sachs presented preliminary information on Barrett, its
natural gas reserves (information that was provided by Barrett management and
was reviewed and adjusted by Plains management), its businesses and other
financial and stock price information, and Goldman Sachs and the Plains Board
discussed the strategic fit between Plains and Barrett. Goldman Sachs and
Batchelder also updated the Plains Board on the expanded study and the
anticipated responses from other potential merger partners or acquirors. Based
on its evaluation of the Barrett proposal, the anticipated results of the
expanded study process, the presentations of Goldman Sachs regarding Barrett
and the discussions regarding the strategic fit between Plains and Barrett, the
Plains Board authorized management, together with Plains' legal and financial
advisors, to negotiate a definitive merger agreement with Barrett to be
presented to the Plains Board of Directors at its next regularly scheduled
meeting to be held on May 2, 1995, four days following the due date for the
preliminary indications of interest based upon the detailed confidential
information materials delivered to the study participants. The Plains Board
also determined that, pending the results of the negotiations with Barrett, the
expanded study would continue unimpeded.
 
  On April 28, Plains received 11 non-binding indications of interest from its
expanded study participants. Seven of these preliminary, non-binding proposals
offered $25.25 or less per share of Plains Common Stock. The four highest
indications of interest consisted of the following: (i) the production
subsidiary of a major oil company submitted a preliminary proposal to acquire
Plains for $300 million (including the assumption of $34.5 million of Plains'
debt), representing $27.21 per share of Plains Common Stock, payable in cash,
stock or a combination of cash and stock; (ii) the production subsidiary of a
second major oil company submitted a proposal substantially identical to the
one described in (i) above, except that a different assumption of the level of
Plains debt was made, resulting in an indication of interest of $26.75 per
share of Plains Common Stock; (iii) the production subsidiary of a large
integrated oil company proposed a range of $23 to $28 per share of Plains
Common Stock, payable in stock or a combination of stock and cash; and (iv) a
privately held oil and natural gas company proposed to acquire at least 51% of
Plains' outstanding shares at a price of $27.50 per share. Each of these
indications of interest was preliminary and nonbinding and subject to
significant contingencies, including due diligence and board and regulatory
approvals.
 
  On April 28, 1995, Barrett's legal advisors met with Plains' legal advisors
in Chicago, and Messrs. Miller and Wallace met with representatives of Barrett
in Denver, to negotiate the terms of the merger agreement. Concurrently,
Barrett's financial advisors, management and independent reserve engineers met
with Plains' financial advisors in Denver to continue the Plains' due diligence
review of Barrett, particularly its natural
 
                                       47
<PAGE>
 
gas reserves. Negotiations between the parties continued in Chicago and Denver
throughout the weekend days of April 29 and 30. Although the parties negotiated
compromises with respect to the size of the termination fee and its triggering
events, the terms of the no-solicitation covenant and issues relating to the
number of Plains Designees, Barrett refused any changes with respect to collars
and walkaways. On May 1, 1995, Barrett informed Plains that its proposal would
expire at 5:00 p.m. (New York City time) on May 2, 1995. Based upon the closing
price of Barrett Common Stock on May 1, 1995, the Barrett proposal represented
an offer of $30.39 per share of Plains Common Stock.
 
  On May 2, 1995, Barrett's Board of Directors met with representatives of
Petrie Parkman and Barrett's legal counsel. The meeting concluded in the late
afternoon of May 2, 1995. Management reported to the Barrett Board of Directors
on the proposed terms of the Merger Agreement. As part of that review, the
Barrett Board of Directors reviewed the final terms of the Merger Agreement
with management and legal counsel, and Petrie Parkman advised the Board of
Directors that, in its opinion, the proposed exchange ratio of 1.3 shares of
Barrett Common Stock for each share of Plains Common Stock was fair from a
financial point of view to the stockholders of Barrett. The Barrett Board of
Directors also analyzed and discussed, together with its legal and financial
advisors, Plains' financial condition, oil and natural gas reserves and
business prospects and the potential synergies that might result from a merger
with Plains. See "--Opinions of Financial Advisors." The Barrett Board of
Directors unanimously approved the Merger Agreement and resolved to recommend
the transaction to its stockholders. See "--Recommendation of the Barrett Board
of Directors; Reasons for the Merger."
 
  On May 2, 1995, the Board of Directors of Plains met for approximately eight
hours with Plains' legal and financial advisors to review the proposed merger.
Plains' management and Goldman Sachs, among other things, reviewed the
information previously supplied by Barrett management and adjusted by Plains
management relating to Barrett's natural gas reserves and discussed the
strategic fit between Plains and Barrett. The Plains Board of Directors also
reviewed with Plains' financial advisors the preliminary, non-binding
indications of interest received from other potential merger partners or
acquirors. Goldman Sachs presented to the Plains Board an analysis described
below under "--Opinions of Financial Advisors--Goldman Sachs Opinion to the
Plains Board of Directors" and advised the Plains Board that, in their opinion,
as of May 2, 1995, the Exchange Ratio pursuant to the Merger Agreement is fair
to the holders of Plains Common Stock. The Board also considered all of the
other factors described below under "--Recommendation of the Plains Boards of
Directors; Reasons for the Merger." At the May 2 meeting, the Board of
Directors of Plains unanimously declared the Merger fair to and advisable and
in the best interests of Plains' stockholders and approved the Merger and the
Merger Agreement, thereby concluding its expanded strategic study.
 
  The Merger Agreement was executed by the parties on May 2, 1995.
 
  On May 9, Cross Timbers filed an amendment to its Schedule 13D stating that
it had sold 229,000 shares of Plains Common Stock between May 3 and May 9 and
that, as of May 9, 1995, Cross Timbers beneficially owned 415,400 shares of
Plains Common Stock (which number did not include the shares in portfolio
accounts managed by a director of Cross Timbers), or approximately 4.2% of the
outstanding shares.
 
RECOMMENDATIONS OF THE BOARDS OF DIRECTORS; REASONS FOR THE MERGER
 
 RECOMMENDATION OF THE BARRETT BOARD OF DIRECTORS; REASONS FOR THE MERGER.  At
a meeting held on May 2, 1995, the Board of Directors of Barrett determined by
unanimous vote that the Merger is fair to and advisable and in the best
interests of the holders of shares of Barrett Common Stock, approved the Merger
Agreement, the Merger and the other transactions contemplated thereby and
resolved to recommend that the holders of shares of Barrett Common Stock vote
in favor of the Charter Amendment and the Stock Issuance.
 
  In reaching these conclusions, the Barrett Board of Directors considered,
with the assistance of management and its legal and financial advisors, among
other things, the following factors:
 
    (i) information concerning the financial performance and condition,
  business operations, assets, liabilities and prospects of Plains and its
  projected future values and prospects as a separate entity and on a
  combined basis with Barrett;
 
                                       48
<PAGE>
 
    (ii) projected operating synergies, expected at this time to include,
  among other things, elimination of duplicative personnel, accounting and
  other systems, and certain other administrative and fixed costs;
 
    (iii) current industry, economic and market conditions;
 
    (iv) the structure of the transaction, including the expected accounting
  treatment of the Merger as a pooling of interests (thereby avoiding the
  reduction in earnings which would result under purchase accounting);
 
    (v) the terms of the Merger Agreement;
 
    (vi) the analyses and recommendation of the transaction by Barrett's
  management;
 
    (vii) the analyses of its financial advisor, including the opinion of
  Petrie Parkman described below as to the fairness to the Barrett
  stockholders of the Exchange Ratio from a financial point of view;
 
    (viii) the strategic fit between Barrett and Plains, including the
  potential impact of combining Barrett's development drilling inventory and
  exploration capabilities and strategy with Plains' strong cash flow;
 
    (ix) the terms of the long-term natural gas purchase contract between
  Plains and K N;
 
    (x) the ability of the combined entity to compete effectively; and
 
    (xi) the increased number of shares of Barrett Common Stock that would be
  held by public shareholders after the Merger, and the likelihood of
  increased liquidity for holders of Barrett Common Stock that would be
  derived therefrom.
 
  In connection with its review of the proposed Merger, the Barrett Board of
Directors also considered that Barrett would have substantially greater proved
oil and natural gas reserves, with a greater percentage of its total reserves
attributable to oil rather than natural gas, compared to Barrett alone, and
that Barrett would continue to be able to benefit from Barrett's and, to a
lesser degree, Plains' exploratory prospects.
 
  The Board of Directors of Barrett believes that the Merger will result in a
combined entity with stronger financial resources that will provide it with the
ability to compete more effectively and take advantage of opportunities that
may not be available to Barrett on its own. The Barrett Board believes that the
Merger will expand the company substantially in a single strategic move and
result in several expected benefits to Barrett and its stockholders, including,
among others: (i) an ability to exploit exploration and production
opportunities from the post-Merger company's solid foundation of long-lived
natural gas production in the Mid-Continent and Rocky Mountains areas and
significant potential from properties in the Piceance, Wind River, Green River,
Powder River, Anadarko, Arkoma and Gulf Coast Basins, (ii) a more diverse oil
and natural gas reserve profile than prior to the transaction, (iii) an
increased ability to compete due to increased size and market presence and (iv)
operating and administrative synergies and efficiencies.
 
  The foregoing discussion of the information and factors considered and given
weight by the Barrett Board of Directors is not intended to be exhaustive. In
view of the variety of factors considered in connection with its evaluation of
the Merger, the Barrett Board of Directors did not find it practicable to and
did not quantify or otherwise assign relative weights to the specific factors
considered in reaching its determination. In addition, individual members of
the Barrett Board of Directors may have given different weights to different
factors. For a discussion of the interests of certain members of Barrett
management and the Barrett Board of Directors in the Merger, see "THE MERGER--
Interests of Certain Persons in the Merger."
 
  THE BARRETT BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT THE HOLDERS OF
BARRETT COMMON STOCK VOTE FOR APPROVAL OF THE CHARTER AMENDMENT AND THE STOCK
ISSUANCE.
 
 RECOMMENDATION OF THE PLAINS BOARD OF DIRECTORS; REASONS FOR THE MERGER.  By
the unanimous vote of the Board of Directors at a meeting held on May 2, 1995,
the Plains Board determined the Merger to be fair to and advisable and in the
best interests of Plains and its stockholders and approved the Merger and the
Merger
 
                                       49
<PAGE>
 
Agreement. As described above under "--Background of the Merger," the Plains
Board's decision to declare the Merger advisable and to approve the Merger and
the Merger Agreement at its May 2nd Board meeting followed a sixteen month
study of strategic alternatives, including an extensive solicitation of
proposals from companies in the energy industry believed to be financially
capable of merging with or acquiring Plains. During this sixteen-month period,
the Plains Board of Directors thoroughly reviewed with Goldman Sachs and
Batchelder Plains' business, results of operations and prospects, including
Plains' existing growth strategy and the uncertainties inherent in achieving
the objectives of such strategy, Plains' stock price performance, the level of
interest solicited from potential merger partners and acquirors, the number and
quality of bids submitted by such study participants and the possible synergies
that might exist with potential merger partners.
 
  At its meeting held on May 2, 1995, the Plains Board received the
presentation of management and the independent presentation of Goldman Sachs
with respect to Barrett, including reviews of, among other things: historical
information relating to the business, financial condition and results of
operations of Barrett; information provided by Barrett management and reviewed
and adjusted by Plains management regarding the natural gas reserves of
Barrett; information regarding the management of Barrett; historical data
relating to market prices and trading volumes of Barrett Common Stock; market
prices for Barrett Common Stock as compared to those of other comparable
publicly traded companies; and the possible effects of the Merger on Barrett's
financial condition and the possible market effects of the announcement of the
proposed Merger and the consummation thereof on the Barrett Common Stock.
Goldman Sachs also presented an analysis of the preliminary indications of
interest received by Plains from the expanded study and a summary comparison of
the Barrett offer with such indications of interest.
 
  During the course of its deliberations, the Plains Board of Directors, with
the assistance of management and its legal and financial advisors, considered a
number of other factors, including the following:
 
    (i) The strategic and financial alternatives available to Plains,
  including remaining a separate company and pursuing its existing growth
  strategy;
 
    (ii) The exchange ratio proposed by Barrett and the implied premium over
  the then current market price of Plains Common Stock as compared to the
  premiums and valuations found in certain other transactions;
 
    (iii) The proposed terms and conditions of the proposed combination of
  Barrett and Plains, including (a) the absence of significant restrictions
  on Plains' ability to consider unsolicited competing merger or acquisition
  proposals from third parties following the execution of the Merger
  Agreement and Plains' ability, subject to certain determinations regarding
  the Plains Board's fiduciary duties, to provide information to, and enter
  into negotiations with, such third parties, (b) the right of Plains to
  terminate the Merger Agreement upon receipt of an offer determined by the
  Plains Board of Directors in good faith to be higher than the per share
  consideration to be received in the Merger, (c) the right of Plains to
  terminate the Merger Agreement upon the occurrence of a material adverse
  change in Barrett, (d) the Plains Board's ability, subject to certain
  determinations regarding the Plains Board's fiduciary duties, to withdraw
  or modify its recommendation to Plains' stockholders and (e) the size and
  structure of the termination fees;
 
    (iv) The results of the initial and expanded study of strategic
  alternatives, the extensive and detailed nature of the confidential
  information delivered to the 22 participants in the expanded study, the
  belief of the Plains management and its financial advisors that additional
  information to be included in a Plains "data room" would not lead to
  materially higher valuations of Plains, the indications of interest
  received by Plains on April 28, 1995 (the highest of which were a non-
  binding indication of interest for approximately $27.21 per share of Plains
  Common Stock and a non-binding indication of interest for a range between
  $23 and $28 per share), the 1.3 exchange ratio (which, based upon the
  closing price of Barrett Common Stock on May 1, 1995, represented an offer
  of $30.39 per share of Plains Common Stock, although the Plains Board was
  aware that the Barrett Common Stock price might be adversely affected, at
  least temporarily, by the announcement of the Merger Agreement), the
  unlikely prospect of
 
                                       50
<PAGE>
 
  materially higher bids (based upon, among other things, the thorough and
  lengthy solicitation of interest that had been conducted, the well-informed
  nature of the preliminary indications of interest and information about
  those companies which had submitted them, the views of Plains' financial
  advisors, as well as the fact that, since the September 19, 1994 Cross
  Timbers Schedule 13D filing, considerable public and industry attention had
  been given to Plains as a takeover candidate), the stated expiration of the
  Barrett proposal at 5:00 p.m. (New York City time) on May 2, 1995 and the
  Board's belief that such offer would be withdrawn if not accepted by, or
  within hours after, the stated deadline;
 
    (v) The strategic fit between Barrett and Plains, including the match of
  Plains' strong cash flow with Barrett's capital intensive development
  drilling inventory and exploration strategy, the complementary location of
  Plains' and Barrett's natural gas producing properties and the
  complementary mix of geological, engineering and production expertise;
 
    (vi) The due diligence investigations of Plains' management and Goldman
  Sachs and presentations of management regarding the strong growth of
  Barrett's natural gas reserves and its prospects for future growth;
 
    (vii) The fact that the combined company after the Merger would be widely
  held and would have a mid-sized equity market capitalization and,
  consequently, that a high premium cash transaction in the future would
  remain a possibility;
 
    (viii) The historical performance and strategic objectives of Barrett, as
  well as the risks involved in achieving those objectives in the oil and
  natural gas industry under current economic and market conditions;
 
    (ix) The preliminary pro forma financial condition, results of operations
  and other financial information of the combined entity, including an
  analysis of the opportunities for cost savings and economies of scale;
 
    (x) The structure of the Merger, which would permit the holders of Plains
  Common Stock to exchange all their shares for shares of Barrett Common
  Stock in a transaction intended, in general, to be tax-free for federal
  income tax purposes except to the extent of cash received in lieu of
  fractional shares of Barrett Common Stock;
 
    (xi) The expected accounting treatment of the Merger as a pooling of
  interests (thereby avoiding the reduction in earnings which would result
  under purchase accounting);
 
    (xii) The likelihood that holders of Plains Common Stock would have
  greater liquidity in their holdings in the combined entity following the
  Merger;
 
    (xiii) The published reports of research analysts regarding Barrett; and
 
    (xiv) The presentations of Goldman Sachs delivered to the Plains Board of
  Directors at its meetings on April 26, 1995 and May 2, 1995, including the
  written opinion of Goldman Sachs delivered at the May 2, 1995 meeting to
  the effect that, as of May 2, 1995, the Exchange Ratio is fair to the
  holders of Plains Common Stock.
 
  Goldman Sachs have delivered a written opinion to the Plains Board of
Directors, dated the date of this Joint Proxy Statement/Prospectus, that, as
of the date hereof, the Exchange Ratio pursuant to the Merger Agreement is
fair to the holders of Plains Common Stock. A copy of the written opinion of
Goldman Sachs dated the date hereof setting forth the assumptions made,
matters considered and limitations on the review undertaken by Goldman Sachs
in rendering their opinion is attached to this Joint Proxy
Statement/Prospectus as Annex III (and is incorporated herein by reference),
and stockholders of Plains are urged to read such opinion carefully in its
entirety. See "--Opinions of Financial Advisors--Goldman Sachs Opinion to the
Plains Board of Directors."
 
  The foregoing discussion of the information and factors considered and given
weight by the Plains Board is not intended to be exhaustive. In view of the
variety of factors considered in connection with its evaluation of the Merger,
the Plains Board of Directors did not find it practicable to and did not
quantify or otherwise assign relative weights to the specific factors
considered in reaching its determination. In addition, individual members of
the Plains Board of Directors may have given different weights to different
factors. For a discussion of the interests of certain members of Plains
management and the Plains Board of Directors in the Merger, see "--Interests
of Certain Persons in the Merger."
 
 
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<PAGE>
 
  BASED ON THE FACTORS DESCRIBED ABOVE, THE PLAINS BOARD OF DIRECTORS
UNANIMOUSLY DECLARED THE MERGER FAIR TO AND ADVISABLE AND IN THE BEST INTERESTS
OF THE HOLDERS OF PLAINS COMMON STOCK. THE BOARD OF DIRECTORS OF PLAINS
UNANIMOUSLY RECOMMENDS TO THE HOLDERS OF PLAINS COMMON STOCK THAT THE MERGER
AND THE MERGER AGREEMENT BE APPROVED AND ADOPTED.
 
OPINIONS OF FINANCIAL ADVISORS
 
  PETRIE PARKMAN OPINION TO THE BARRETT BOARD OF DIRECTORS. The Barrett Board
of Directors engaged Petrie Parkman to act as its financial advisor in
connection with the Merger. The Barrett Board instructed Petrie Parkman, in its
role as financial advisor, to evaluate the fairness, from a financial point of
view, to the holders of Barrett Common Stock of the Exchange Ratio of 1.3
shares of Barrett Common Stock for each share of Plains Common Stock in
connection with the Merger and, in such regard, to conduct such investigations
as Petrie Parkman deemed appropriate for such purpose. Petrie Parkman advised
the Barrett Board, in its written opinion dated May 2, 1995, that, as of May 2,
1995, the Exchange Ratio in connection with the Merger is fair, from a
financial point of view, to the holders of Barrett Common Stock. Petrie Parkman
subsequently delivered its written opinion to the Barrett Board that, as of the
date hereof, the Exchange Ratio is fair, from a financial point of view, to the
holders of Barrett Common Stock.
 
  THE FULL TEXT OF PETRIE PARKMAN'S WRITTEN OPINION DATED AS OF THE DATE
HEREOF, WHICH CONTAINS A DESCRIPTION OF THE ASSUMPTIONS MADE, THE MATTERS
CONSIDERED BY PETRIE PARKMAN, AND THE LIMITS OF ITS REVIEW, IS ATTACHED HERETO
AS ANNEX II AND IS INCORPORATED HEREIN BY REFERENCE. STOCKHOLDERS ARE
ENCOURAGED TO READ THE OPINION CAREFULLY IN ITS ENTIRETY. In rendering its
opinion, Petrie Parkman relied upon the accuracy and completeness of the
financial, operating, and other information provided to it and assumed that
such information had been reasonably prepared on bases reflecting the best
currently available estimates and judgments. Petrie Parkman did not
independently verify such information or make independent evaluations or
appraisals of the assets or liabilities of Barrett or Plains nor, except for
the reserve reports referred to in its opinion, was Petrie Parkman furnished
with any such evaluations or appraisals. Petrie Parkman's opinion relates only
to the Exchange Ratio in connection with the Merger and does not constitute a
recommendation to any holder of Barrett Common Stock as to how such holder
should vote at the Barrett Special Meeting.
 
  In connection with its opinion, Petrie Parkman, among other things (i)
reviewed certain publicly-available business and financial information relating
to Plains and Barrett, including, among others, audited financial statements
for Plains as of December 31, 1994 and for Barrett as of September 30, 1994 and
unaudited financial and operating information for Barrett as of February 28,
1995; (ii) reviewed the estimates of proved oil and natural gas reserves as
prepared by Netherland Sewell & Associates, Inc. for Plains as of December 31,
1994 and as reviewed by Ryder Scott Company for Barrett as of September 30,
1994 and as of March 31, 1995 (the "Reserve Reports"); (iii) reviewed certain
estimates of oil and natural gas reserves of Plains and Barrett as of January
1, 1995 as prepared by their respective management and staff; (iv) analyzed
certain internal financial and operating forecasts and financial and operating
data concerning Plains and Barrett, all of which were prepared or provided by
the management of Plains or Barrett; (v) discussed the current operations and
prospects of Plains with the management and operating staff of Plains and
Barrett; (vi) discussed with the management and operating staff of Barrett the
current operations and prospects of Barrett and the expected operations and
prospects of the combined company, giving pro forma effect to the Merger,
including the operational efficiencies expected by Barrett to be realized from
the Merger; (vii) reviewed the historical market prices of the shares of
Barrett Common Stock and Plains Common Stock; (viii) compared the financial
terms of the Merger with the financial terms of certain other transactions
which it deemed to be relevant; and (ix) made such other analyses and
examinations as it deemed necessary or appropriate.
 
  In rendering its opinion, Petrie Parkman conducted several analyses including
(i) discounted cash flow analyses of each of Barrett and Plains ("Discounted
Cash Flow Analyses"); (ii) comparisons with selected publicly-traded comparable
companies ("Common Stock Comparisons"); (iii) analyses of selected comparable
industry transactions ("Comparable Transactions Analyses"); (iv) an analysis of
the potential future financial
 
                                       52
<PAGE>
 
performance of Barrett ("Going Concern Analysis"); and (v) an analysis of the
potential financial effects of the Merger ("Pro Forma Merger Analysis"). These
analyses are described below. Based upon the reference value ranges resulting
from the various analyses and subject to the assumptions and limitations set
forth in its opinion, Petrie Parkman came to composite ranges of asset
reference values for Barrett and Plains of $275 million to $325 million and
$280 million to $350 million, respectively. After deducting long-term debt for
Barrett of approximately $31 million from the Barrett composite asset reference
value range and dividing by the number of shares of Barrett Common Stock
outstanding, Petrie Parkman arrived at a composite equity reference value range
per share of Barrett Common Stock on a primary basis of $20.56 to $24.78. After
deducting long-term debt for Plains of approximately $37 million from the
Plains composite asset reference value range and dividing by the number of
shares of Plains Common Stock outstanding, Petrie Parkman arrived at a
composite equity reference value range per share of Plains Common Stock on a
primary basis of $24.76 to $31.90.
 
  DISCOUNTED CASH FLOW ANALYSIS--BARRETT. Under this analysis, Petrie Parkman
calculated estimates of future after-tax cash flows for the reserve assets of
Barrett based on the Reserve Reports and certain projections provided by
Barrett and for the non-reserve assets of Barrett utilizing information and
projections provided by Barrett. Three scenarios were evaluated in which the
principal variables were oil and natural gas prices. The three pricing
scenarios used by Petrie Parkman were based on benchmarks for posted prices for
West Texas Intermediate equivalent crude oil and for spot sales of Louisiana
offshore natural gas delivered to an interstate pipeline ("Pricing Case I,"
"Pricing Case II" and "Pricing Case III"). To these benchmarks, Petrie Parkman
applied appropriate quality and transportation adjustments. For Pricing Cases
I, II and III, benchmark oil prices were projected to be $16.00, $17.50 and
$19.00 per barrel, respectively, for 1995 and to escalate annually thereafter
at rates of 4.0%, 5.0% and 6.0%, respectively; oil prices in each pricing case
were capped at $50.00 per barrel. Benchmark natural gas prices were projected
to be $1.65, $1.85 and $2.00 per MMBtu, respectively, for 1995 and to escalate
annually thereafter at rates of 5.0%, 5.0% and 6.0%, respectively; natural gas
prices in each pricing case were capped at $6.00 per MMBtu. Operating and
capital costs were escalated at 4.0% per year. Other factors involved in this
analysis included the use of after-tax discount rates ranging from 10.0% to
17.5%, a carry-over of Barrett's existing tax positions, and the evaluation of
certain other assets of Barrett. This methodology resulted in asset reference
value ranges of $196 million to $252 million for Pricing Case I, $219 million
to $278 million for Pricing Case II and $245 million to $309 million for
Pricing Case III.
 
  COMMON STOCK COMPARISON--BARRETT. Using publicly-available information,
Petrie Parkman calculated adjusted capitalization multiples of certain
historical financial criteria (such as gross pretax cash flow, adjusted
discretionary cash flow, operating cash flow, and standardized measure of
discounted future net cash flows ("SEC Value")) and of equivalent proved
reserves, and market capitalization multiples of certain historical financial
criteria (such as discretionary cash flow) for 62 publicly-traded U.S.-based
independent oil and natural gas companies with adjusted capitalizations less
than $750 million. The adjusted capitalization of each company was obtained by
adding its long-term and short-term debt to the sum of the market value of its
common equity, the market value of its preferred stock (if publicly-traded or
liquidation or book value if not) and the book value of its minority interest
in other companies minus its cash balance. Petrie Parkman then segmented the 62
companies into two categories (U.S. oil and natural gas explorers and U.S.
natural gas producers) based on its judgments regarding the operational
characteristics and growth strategies of each company.
 
  Five of these companies--Cairn Energy USA, Inc., Chesapeake Energy
Corporation, Stone Energy Corporation, Texas Meridian Resources Corporation and
Tom Brown, Inc.--which in Petrie Parkman's judgment were more relevant to an
evaluation of Barrett as a U.S. oil and natural gas explorer, were examined in
greater detail. For these five companies, the highest, average, and lowest
adjusted capitalization multiples of gross pretax cash flow were 30.6x, 25.1x
and 9.4x, respectively. The highest, average and lowest adjusted capitalization
multiples of adjusted discretionary cash flow were 27.7x, 22.3x and 9.0x,
respectively. The highest, average and lowest adjusted capitalization multiples
of operating cash flow were 24.0x, 18.3x and 8.0x, respectively. The highest,
average and lowest adjusted capitalization multiples of SEC Value were 5.0x,
 
                                       53
<PAGE>
 
2.8x and 1.9x, respectively. The highest, average and lowest adjusted
capitalization multiples of equivalent proved reserves were $6.24, $2.70 and
$1.02 per Mcf equivalent using a six Mcf of natural gas to one barrel of oil
conversion ratio ("Mcfe6"), respectively. The highest, average and lowest
market capitalization multiples of discretionary cash flow were 29.1x, 23.9x
and 9.2x, respectively. Petrie Parkman determined that, with respect to
Barrett, the appropriate benchmark for adjusted capitalization multiples for
gross pretax cash flow, adjusted discretionary cash flow, operating cash flow,
SEC Value and equivalent proved reserves were in the ranges of 25.0 to 30.0x,
25.0 to 30.0x, 18.0 to 23.0x, 2.0 to 3.0x, and $1.75 to 2.25 per Mcfe6,
respectively, and that the appropriate benchmark market capitalization
multiples for discretionary cash flow were in the range of 25.0 to 30.0x. These
benchmark multiples were applied by Petrie Parkman to Barrett's gross pretax
cash flow, adjusted discretionary cash flow, operating cash flow, SEC Value,
discretionary cash flow and equivalent proved reserves, respectively, all of
which were derived from publicly-available financial and operating data for
Barrett. From the asset reference value ranges implied by these multiples,
Petrie Parkman determined a composite asset reference value range under this
method of $260 million to $330 million.
 
  Thirteen of these companies--Basin Exploration, Inc., Cabot Oil & Gas
Corporation, Cross Timbers Oil Company, Devon Energy Corporation, Gerrity Oil &
Gas Corporation, HS Resources, Inc., Hugoton Energy Corporation, PetroCorp,
Inc., Plains Petroleum Company, Presidio Oil Company, St. Mary Land &
Exploration Company, Tide West Oil Company and Unit Corporation--which in
Petrie Parkman's judgment were more relevant to an evaluation of Barrett as a
U.S. natural gas producer, were examined in greater detail. For these thirteen
companies, the highest, average and lowest adjusted capitalization multiples of
gross pretax cash flow were 12.3x, 7.8x and 5.0x, respectively. The highest,
average and lowest adjusted capitalization multiples of adjusted discretionary
cash flow were 9.9x, 7.8x and 5.0x, respectively. The highest, average and
lowest adjusted capitalization multiples of operating cash flow were 9.4x, 6.4x
and 4.0x, respectively. The highest, average and lowest adjusted capitalization
multiples of SEC Value were 1.7x, 1.4x and 1.1x, respectively. The highest,
average and lowest adjusted capitalization multiples of equivalent proved
reserves were $0.95, $0.76 and $0.60 per Mcfe6, respectively. The highest,
average and lowest market capitalization multiples of discretionary cash flow
were 8.3x, 5.3x and -1.0x, respectively. Petrie Parkman determined that, with
respect to Barrett, the appropriate benchmark adjusted capitalization multiples
for gross pretax cash flow, adjusted discretionary cash flow, operating cash
flow, SEC Value and equivalent proved reserves were in the ranges of 7.0 to
9.0x, 7.0 to 9.0x, 5.0 to 7.0x, 1.2 to 1.5x, and $0.70 to 0.85 per Mcfe6,
respectively, and that the appropriate benchmark market capitalization
multiples for discretionary cash flow were in the range of 5.0 to 7.0x. These
benchmark multiples were applied by Petrie Parkman to Barrett's gross pretax
cash flow, adjusted discretionary cash flow, operating cash flow, SEC Value and
discretionary cash flow derived from publicly-available financial and operating
data and equivalent proved reserves based on the Reserve Reports and certain
projections provided by Barrett. From the asset reference value ranges implied
by these multiples, Petrie Parkman determined a composite asset reference value
range under this method of $200 million to $250 million.
 
  COMPARABLE TRANSACTIONS ANALYSIS--BARRETT. Petrie Parkman reviewed certain
publicly-available information on 84 oil and natural gas property acquisition
transactions involving Rocky Mountain and Mid-Continent assets which took place
between January 1993 and April 1995. Using publicly-available information,
Petrie Parkman calculated purchase price multiples of equivalent proved
reserves for the acquired assets in each transaction. The highest, average and
lowest multiples of equivalent proved reserves were $1.58, $0.75 and $0.20 per
Mcfe6, respectively. The highest, average and lowest multiples of equivalent
proved reserves using a 10 Mcf of natural gas to one barrel of oil conversion
("Mcfe10") were $1.58, $0.61 and $0.12, respectively. Petrie Parkman determined
that, with respect to Barrett, the appropriate benchmark multiples for
equivalent proved reserves were in the ranges of $0.80 to $0.95 per Mcfe6 and
$0.75 to $0.90 per Mcfe10, respectively. These benchmarks were applied by
Petrie Parkman to Barrett's corresponding proved reserve figures based on the
Reserve Reports and certain projections provided by Barrett to yield asset
reference value ranges for Barrett's reserves. Following adjustments for
Barrett's non-reserve assets, Petrie Parkman determined from the asset
reference value ranges implied by these multiples a composite asset reference
value range under this method of $264 million to $321 million.
 
                                       54
<PAGE>
 
  In addition, Petrie Parkman reviewed certain publicly-available information
on 18 company acquisition transactions and offers for control in the oil and
natural gas exploration and production industry which took place between
January 1992 and April 1995. Using publicly-available information, Petrie
Parkman calculated total investment (purchase price plus obligations assumed)
multiples of gross pretax cash flow for the target company in each transaction.
For these 18 transactions, the highest, average and lowest multiples of gross
pretax cash flow were 15.1x, 6.5x and -14.0x, respectively. Petrie Parkman also
calculated purchase price multiples of discretionary cash flow and implied
purchase price of reserves (purchase price plus obligations assumed less
estimated values of non-reserve assets) multiples of SEC Value and equivalent
proved reserves for the target company in each transaction. The highest,
average and lowest purchase price multiples of discretionary cash flow were
23.0x, 6.8x and -10.7x, respectively. The highest, average and lowest implied
purchase price multiples of SEC Value were 2.0x, 1.3x and 0.5x, respectively.
The highest, average and lowest implied purchase price multiples of equivalent
proved reserves were $1.64, $0.85 and $0.33 per Mcfe6, respectively. The
highest, average and lowest implied purchase price multiples of equivalent
proved reserves were $1.51, $0.73 and $0.22 per Mcfe10, respectively. Petrie
Parkman determined that, with respect to Barrett, the appropriate benchmark
multiples for gross pretax cash flow, discretionary cash flow, SEC Value and
equivalent proved reserves were in the ranges of 7.0 to 9.0x, 8.0 to 11.0x, 1.5
to 1.8x, $0.80 to $0.95 per Mcfe6, and $0.75 to 0.90 per Mcfe10, respectively.
These benchmark multiples were applied by Petrie Parkman to Barrett's gross
pretax cash flow, discretionary cash flow, SEC Value and equivalent proved
reserves based on the Reserve Reports and certain projections provided by
Barrett. Following adjustments for Barrett's non-reserve assets as appropriate,
Petrie Parkman determined from the asset reference value ranges implied by
these multiples a composite asset reference value range under this method of
$200 million to $250 million.
 
  GOING CONCERN ANALYSIS--BARRETT. Under this analysis, Petrie Parkman
projected cash flows for Barrett without giving effect to the Merger for the
five year period 1995 through 1999 using the three oil and natural gas pricing
scenarios described above. These projections were prepared utilizing certain
information and projections prepared or provided by Barrett management as well
as numerous assumptions, including two capital spending cases ("Capital Case I"
and "Capital Case II", respectively) and a 1995 reserve finding cost of $0.55
per Mcfe6. The two capital cases differed in the amount and timing of capital
expended over the five year period and the $0.55 per Mcfe6 reserve finding cost
was based on a five year average of Barrett's historical reserve finding costs.
Other factors included discount rates of 12.5% to 15.0%, terminal multiples of
6.0x projected 1999 discretionary cash flow and $1.10 per Mcfe6 of projected
1999 reserves and Barrett's existing tax positions.
 
  This methodology resulted in ranges of equity reference values per share of
Barrett (on a primary basis) using a terminal multiple of 6.0x projected 1999
discretionary cash flow under Capital Case I of $18.16 to $20.75 using Pricing
Case I, $25.85 to $29.17 using Pricing Case II, and $32.05 to $35.93 using
Pricing Case III and under Capital Case II of $21.08 to $24.30 using Pricing
Case I, $32.25 to $36.60 using Pricing Case II, and $40.62 to $45.77 using
Pricing Case III. Use of a terminal multiple of $1.10 per Mcfe6 for projected
1999 reserves yielded equity reference values per share of Barrett (on a
primary basis) under Capital Case I of $20.06 to $22.89 using Pricing Case I,
$23.82 to $26.88 using Pricing Case II, and $27.41 to $30.70 using Pricing Case
III and under Capital Case II of $24.05 to $27.64 using Pricing Case I, $28.52
to $32.39 using Pricing Case II, and $32.81 to $36.97 using Pricing Case III.
From these equity reference value ranges, Petrie Parkman determined composite
asset reference value ranges under this method of $316 million to $375 million
for Capital Case I and $399 million to $458 million for Capital Case II,
respectively.
 
  PRO FORMA MERGER ANALYSIS. Petrie Parkman analyzed certain pro forma
financial effects from the Merger projected for the periods 1995 through 1999
after considering the aforementioned information. In connection with such
analysis, Petrie Parkman assessed the past performance of the management of
Barrett, reviewed the estimates and projections prepared or provided by the
managements of Barrett and Plains, and had discussions with members of the
management of Barrett with respect to the future financial and operating
performance of Barrett on a stand-alone basis and after giving effect to the
Merger, but relied only to a limited
 
                                       55
<PAGE>
 
degree on these estimates and projections in conducting its pro forma merger
analysis. This analysis indicated that the contemplated transaction would be
anti-dilutive to projected Barrett earnings per share and discretionary cash
flow per share. Petrie Parkman concluded that, based on these projections, the
contemplated transaction would not be dilutive over the period analyzed and
would not result in higher financial leverage, thus supporting its opinion.
 
  DISCOUNTED CASH FLOW ANALYSIS--PLAINS. Under this analysis, Petrie Parkman
calculated estimates of future after-tax cash flows for the reserve assets of
Plains based on the Reserve Reports and certain projections provided by Plains
and for the non-reserve assets of Plains utilizing information and projections
provided by Plains. Three scenarios were evaluated in which the principal
variables were the oil and natural gas price scenarios described above. Other
factors involved in this analysis included the use of after-tax discount rates
ranging from 10.0% to 20.0%, a carry-over of Plains' existing tax positions,
and the evaluation of certain other assets of Plains. This methodology resulted
in asset reference value ranges of $217 million to $266 million for Pricing
Case I, $251 million to $303 million for Pricing Case II, and $290 million to
$349 million for Pricing Case III.
 
  COMMON STOCK COMPARISONS--PLAINS. Using publicly-available information,
Petrie Parkman calculated adjusted capitalization multiples of certain
historical financial criteria (such as gross pretax cash flow, adjusted
discretionary cash flow, operating cash flow and SEC Value) and of equivalent
proved reserves, and market capitalization multiples of certain historical
financial criteria (such as discretionary cash flow) for 62 publicly-traded
U.S.-based independent oil and natural gas companies with adjusted
capitalizations less than $750 million. Fourteen of these companies, which in
Petrie Parkman's judgment were more relevant to an evaluation of Plains, were
examined in greater detail: Barrett Resources Corporation, Coda Energy, Inc.,
Cross Timbers Oil Company, Devon Energy Corporation, Hugoton Energy
Corporation, Lomak Petroleum, Inc., Louis Dreyfus Gas Corporation, PetroCorp,
Inc., Presidio Oil Company, St. Mary Land & Exploration Company, Swift Energy
Company, Tide West Oil Company, Unit Corporation and The Wiser Oil Company. For
these 14 companies, the highest, average and lowest adjusted capitalization
multiples of gross pretax cash flow were 28.4x, 9.8x and 4.9x, respectively.
The highest, average and lowest adjusted capitalization multiples of adjusted
discretionary cash flow were 26.3x, 9.6x and 4.9x, respectively. The highest,
average and lowest adjusted capitalization multiples of operating cash flow
were 18.7x, 7.7x and 4.0x, respectively. The highest, average and lowest
adjusted capitalization multiples of SEC Value were 3.9x, 1.6x and 1.1x,
respectively. The highest, average and lowest adjusted capitalization multiples
of equivalent proved reserves were $1.83, $0.91 and $0.61 per Mcfe6,
respectively. The highest, average and lowest market capitalization multiples
of discretionary cash flow were 25.9x, 7.2x and -1.3x, respectively. Petrie
Parkman determined that, with respect to Plains, the appropriate benchmark
adjusted capitalization multiples for gross pretax cash flow, adjusted
discretionary cash flow, operating cash flow, SEC Value and equivalent proved
reserves were in the ranges of 8.0 to 9.5x, 8.0 to 9.5x, 6.0 to 8.0x, 1.4 to
1.6x, and $0.85 to 0.95 per Mcfe6, respectively, and that the appropriate
benchmark market capitalization multiples for discretionary cash flow were in
the range of 6.0 to 8.0x. These benchmark multiples were applied by Petrie
Parkman to Plains' gross pretax cash flow, adjusted discretionary cash flow,
operating cash flow, SEC Value and discretionary cash flow, derived from
publicly-available financial and operating data and equivalent proved reserves
based on the Reserve Reports and certain projections provided by Plains. From
the asset reference value ranges implied by these multiples, Petrie Parkman
determined a composite asset reference value range under this method of $260
million to $330 million.
 
  COMPARABLE TRANSACTIONS ANALYSIS--PLAINS. Petrie Parkman reviewed certain
publicly-available information on 84 oil and natural gas property acquisition
transactions involving Rocky Mountain and Mid-Continent assets which took place
between January 1993 and April 1995. Using publicly-available information,
Petrie Parkman calculated purchase price multiples of equivalent proved
reserves for the acquired assets in each transaction. The highest, average and
lowest multiples of equivalent proved reserves were $1.58, $0.75 and $0.20 per
Mcfe6, respectively. The highest, average and lowest multiples of equivalent
proved reserves were $1.58, $0.61 and $0.12 per Mcfe10, respectively. Petrie
Parkman determined that, with
 
                                       56
<PAGE>
 
respect to Plains, the appropriate benchmark multiples for equivalent proved
reserves were in the ranges of $0.75 to $0.90 per Mcfe6 and $0.65 to $0.85 per
Mcfe10, respectively. These benchmarks were applied by Petrie Parkman to
Plains' corresponding proved reserve figures based on the Reserve Reports and
certain projections provided by Plains to yield asset reference value ranges
for Plains' reserves. Following adjustments for Plains' non-reserve assets,
Petrie Parkman determined from the asset reference value ranges implied by
these multiples a composite asset reference value range under this method of
$288 million to $372 million.
 
  In addition, Petrie Parkman reviewed certain publicly-available information
on 18 company acquisition transactions and offers for control in the oil and
natural gas exploration and production industry which took place between
January 1992 and April 1995. Using publicly-available information, Petrie
Parkman calculated total investment multiples of gross pretax cash flow for
the target company in each transaction. For these 18 transactions, the
highest, average and lowest multiples of gross pretax cash flow were 15.1x,
6.5x and -14.0x, respectively. Petrie Parkman also calculated purchase price
multiples of discretionary cash flow and implied purchase price of reserves
multiples of SEC Value and equivalent proved reserves for the target company
in each transaction. The highest, average and lowest purchase price multiples
of discretionary cash flow were 23.0x, 6.8x and -10.7x, respectively. The
highest, average and lowest implied purchase price multiples of SEC Value were
2.0x, 1.3x and 0.5x, respectively. The highest, average and lowest implied
purchase price multiples of equivalent proved reserves were $1.64, $0.85 and
$0.33 per Mcfe6, respectively. The highest, average and lowest implied
purchase price multiples of equivalent proved reserves were $1.51, $0.73 and
$0.22 per Mcfe10, respectively. Petrie Parkman determined that, with respect
to Plains, the appropriate benchmark multiples for gross pretax cash flow,
discretionary cash flow and SEC Value and equivalent proved reserves were in
the ranges of 7.0 to 9.5x, 7.5 to 9.5x, 1.5 to 2.0x, $0.75 to $1.00 per Mcfe6
and $0.70 to 0.95 per Mcfe10, respectively. These benchmark multiples were
applied by Petrie Parkman to Plains' gross pretax cash flow, discretionary
cash flow and SEC Value derived from publicly-available financial and
operating data and equivalent proved reserves based on the Reserve Reports and
certain projections provided by Plains. Following adjustments for Plains' non-
reserve assets as appropriate, Petrie Parkman determined from the asset
reference value ranges implied by these multiples a composite asset reference
value range under this method of $270 million to $360 million.
 
  The description set forth above constitutes a summary of the material
analyses and assumptions employed by Petrie Parkman in rendering its opinion
to the Barrett Board of Directors. Petrie Parkman believes that it analyses
must be considered as a whole and that selecting portions of its analyses or
the factors considered by it, without considering all analyses and factors,
could create an incomplete view of the process underlying its opinion. The
preparation of a fairness opinion is a complex process, judgmental in nature
and not necessarily susceptible to partial analysis or summary description. In
its analyses, Petrie Parkman made numerous assumptions with respect to
industry performance, capital market conditions, general business and economic
conditions and other matters, many of which are beyond the control of Barrett
and Plains. Any estimates contained therein are not necessarily indicative of
actual values, which may be significantly more or less favorable than as set
forth therein. Estimates of reference values of companies do not purport to be
appraisals or necessarily reflect the prices at which companies may actually
be sold. Because such estimates are inherently subject to uncertainty, no
assurances can be given that such estimates will prove to be accurate.
 
  Petrie Parkman confirmed, as of the date of this Joint Proxy
Statement/Prospectus, its opinion of May 2, 1995 that the Exchange Ratio in
connection with the Merger is fair to the holders of Barrett Common Stock from
a financial point of view. In rendering such confirmation, Petrie Parkman
performed procedures to update certain of its analyses made in connection with
its May 2, 1995 opinion and reviewed the assumptions on which such analyses
were based and the factors considered in connection therewith. Petrie Parkman
considered, among other things, Barrett's and Plains' recent financial
performance and recent market conditions and developments based on the
foregoing.
 
  As described above, Petrie Parkman's opinion and presentation to the Barrett
Board of Directors was one of many factors taken into consideration by the
Barrett Board of Directors in making its determination to approve and
recommend the transaction contemplated in the Merger Agreement.
 
                                      57
<PAGE>
 
  Petrie Parkman, as part of its investment banking business, is continually
engaged in the evaluation of energy-related businesses and their securities in
connection with mergers and acquisitions, negotiated underwritings, secondary
distributions of listed and unlisted securities, private placements and
valuations for corporate and other purposes. Barrett selected Petrie Parkman as
its financial advisor because it is a nationally-recognized investment banking
firm that has substantial experience in transactions similar to the Merger.
 
  Pursuant to the terms of the engagement letter dated February 21, 1995,
Barrett has paid Petrie Parkman an advisory fee of $75,000 and a fee in
connection with rendering its opinion of $150,000. In addition, Barrett has
agreed to pay Petrie Parkman a transaction fee based on the total value of the
Merger. Such transaction fee, after crediting the advisory fee, is
approximately $2.5 million, and is contingent upon and payable following
consummation of the Merger. Whether or not the Merger is consummated, Barrett
has also agreed to reimburse Petrie Parkman for its out-of-pocket expenses,
including reasonable fees and expenses of counsel, and to indemnify Petrie
Parkman and certain related persons against certain liabilities relating to or
arising out of its engagement, including certain liabilities under the federal
securities laws. Petrie Parkman has, in the past, performed certain other
investment banking services for Barrett.
 
  GOLDMAN SACHS OPINION TO THE PLAINS BOARD OF DIRECTORS. On May 2, 1995,
Goldman Sachs delivered their written opinion to the Board of Directors of
Plains that as of May 2, 1995, the Exchange Ratio pursuant to the Merger
Agreement is fair to the holders of the Plains Common Stock. Goldman Sachs
subsequently delivered their written opinion to the Board of Directors of
Plains that as of the date hereof, the Exchange Ratio is fair to the holders of
Plains Common Stock.
 
  THE FULL TEXT OF THE WRITTEN OPINION OF GOLDMAN SACHS, DATED THE DATE HEREOF,
WHICH SETS FORTH ASSUMPTIONS MADE, MATTERS CONSIDERED AND LIMITATIONS ON THE
REVIEW UNDERTAKEN IN CONNECTION WITH THE OPINION, IS ATTACHED HERETO AS ANNEX
III TO THIS JOINT PROXY STATEMENT/PROSPECTUS AND IS INCORPORATED HEREIN BY
REFERENCE. STOCKHOLDERS OF PLAINS ARE URGED TO, AND SHOULD, READ THE OPINION IN
ITS ENTIRETY.
 
  In connection with their opinion, Goldman Sachs reviewed, among other things,
(i) the Merger Agreement; (ii) the Annual Reports to Stockholders and Annual
Reports on Form 10-K of Plains for the five years ended December 31, 1994 and
of Barrett for the five fiscal years ended September 30, 1994; (iii) certain
interim reports to stockholders and Quarterly Reports on Form 10-Q of Plains
and Barrett; (iv) certain other communications from Plains and Barrett to their
respective stockholders; and (v) certain internal financial analyses and
forecasts for Plains and Barrett prepared by their respective managements.
Goldman Sachs also held discussions with members of the senior management of
Plains and Barrett regarding the past and current business operations,
financial condition, and future prospects of their respective companies.
 
  In connection with their opinion, Goldman Sachs also reviewed certain
information provided by Plains and Barrett relating to their respective oil and
natural gas reserves, including year-end reserve reports of Plains prepared by
independent petroleum engineers for Plains, and year-end reserve reports of
Barrett prepared by Barrett and reviewed by independent petroleum engineers for
Barrett, as well as interim estimates prepared by Plains and Barrett, including
a review of estimated reserves of Barrett as of March 31, 1995 prepared by
Barrett and reviewed by independent petroleum engineers for Barrett, and
discussed the reserve information with the respective managements of Plains and
Barrett and such independent petroleum engineers. Goldman Sachs also held
discussions with members of the senior management of Plains and its independent
petroleum engineers regarding their due diligence examination of such reserve
information for Barrett.
 
  In addition, Goldman Sachs reviewed the reported price and trading activity
for the Plains Common Stock and the Barrett Common Stock, compared certain
financial and stock market information for Plains and Barrett with similar
information for certain other companies the securities of which are publicly
traded, reviewed the financial terms of certain recent business combinations in
the oil and natural gas industry specifically and in other industries generally
and performed such other studies and analyses as they considered appropriate.
 
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<PAGE>
 
  Goldman Sachs relied without independent verification upon the accuracy and
completeness of all of the financial and other information reviewed by them for
purposes of their opinion. Goldman Sachs did not make an independent evaluation
or appraisal of the assets and liabilities of Plains or Barrett or any of their
respective subsidiaries and, except for the reserve information referred to
above, have not been furnished with any such evaluation or appraisal. With
respect to such reserve information, Goldman Sachs are not experts in the
evaluation of oil and natural gas properties and relied solely upon the reserve
reports and internal estimates prepared by the independent petroleum engineers
and managements of Plains and Barrett and, with Plains' consent, assumed that
such information and the forecasts provided to them were reasonably prepared on
bases reflecting Plains' management's best available judgments and estimates at
the time of their preparation and that the amounts reflected therein will be
realized in the amounts and at the times set forth therein. Goldman Sachs'
opinion is based upon economic and market conditions existing on the date of
their opinion.
 
  The following is a summary of certain of the financial analyses used by
Goldman Sachs in connection with providing their written opinion to Plains'
Board of Directors on May 2, 1995. Goldman Sachs utilized substantially the
same type of financial analyses in connection with providing the written
opinion dated the date hereof attached hereto as Annex III.
 
  SELECTED COMPANIES ANALYSIS. Goldman Sachs reviewed and compared certain
financial information, ratios and public market multiples relating to Plains
and Barrett to corresponding financial information, ratios and public market
multiples for a number of publicly traded oil and natural gas companies as well
as for composites of publicly traded oil and natural gas companies, including a
broad-based composite of independent exploration and production companies (the
"Independents Composite") and a composite of exploration and production
companies growing primarily through exploration (the "Exploration Composite").
The multiples and ratios for each of the referenced companies, including Plains
and Barrett, were based on the most recent publicly available information. In
performing their analysis, Goldman Sachs calculated, among other things, the
following multiples and ratios (the "Ratios"): (i) the closing market price of
a share of stock of the relevant company on April 28, 1995 to estimated 1995
and 1996 discretionary cash flow ("DCF") multiples (the "1995 and 1996
Price/DCF Multiples"); (ii) the closing market price of a share of stock of the
relevant company on April 28, 1995 to estimated 1995 unleveraged DCF (i.e., DCF
plus interest expense and preferred dividends) multiple (the "Unlevered 1995
DCF Multiple"); and (iii) total capitalization as of April 28, 1995 (i.e.,
market value of equity plus total debt, minus working capital) (the "Total
Capitalization") divided by thousands of cubic feet of natural gas equivalent
of proved reserves ("Mcfe") (at a ratio of six Mcf per barrel of oil) as of
each respective company's 1994 fiscal year end (the "Mcfe Value"). The
composite Ratios were, in each case, based upon the mean values for each of the
companies making up the composite.
 
  With respect to Plains, Goldman Sachs' analysis indicated that (i) the 1995
and 1996 Price/DCF Multiples were 5.6 and 5.4, respectively, for Plains and 6.4
and 4.5, respectively, for the Independents Composite, (ii) the Unlevered 1995
DCF Multiple was 6.1 for Plains and 7.2 for the Independents Composite, and
(iii) the Mcfe Value was $0.70 for Plains and $1.32 for the Independents
Composite. With respect to Barrett, Goldman Sachs' analysis indicated that (i)
the 1995 and 1996 Price/DCF Multiples were 13.4 and 7.5, respectively, for
Barrett and 8.7 and 5.8, respectively, for the Exploration Composite, (ii) the
Unlevered 1995 DCF Multiple was 13.0 for Barrett and 8.8 for the Exploration
Composite, and (iii) the Mcfe Value was $1.97 for Barrett and $1.54 for the
Exploration Composite.
 
  Goldman Sachs also reviewed certain historical price information for the
Plains Common Stock and the Barrett Common Stock and compared the information
with price information for other companies in the oil and natural gas industry.
 
  SELECTED TRANSACTIONS ANALYSIS. Goldman Sachs analyzed certain publicly
available ratio and multiple information relating to selected transactions in
the oil and natural gas industry since 1993 (the "Selected Transactions"). The
analysis indicated that valuations per Mcfe of reserves for the Selected
Transactions
 
                                       59
<PAGE>
 
ranged from $0.67 to $1.54, with a mean of $0.98 and a median of $0.91, as
compared with an indicated Mcfe Value of $0.88 for Plains assuming the Merger
had occurred at the April 28, 1995 pre-Merger announcement Barrett Common Stock
price of $23.50. The analysis also indicated that the equity consideration as a
multiple of latest 12 months' cash flow for the Selected Transactions ranged
from 3.5 to 13.9, with a mean of 8.4 and a median of 8.2, as compared with an
equity consideration as a multiple of latest 12 months' cash flow of 10.2 for
Plains, assuming the Merger occurred at the pre-Merger announcement Barrett
Common Stock price of $23.50.
 
  ANALYSIS AT VARIOUS PRICES. Goldman Sachs compared the Exploration Composite
Ratios and the Independents Composite Ratios to the post-Merger company Ratios
that would exist at different stock prices of the post-Merger company. The
multiples and ratios for the post-Merger company were based on information
provided by Plains' and Barrett's managements. Each of the post-Merger company
stock prices discussed below should be multiplied by the Exchange Ratio to
determine the corresponding price per share of Plains Common Stock.
 
  The 1995 Price/DCF Multiple for the Exploration Composite and Independents
Composite was 8.7 and 6.4, respectively, levels which correspond to a post-
Merger company stock price ranging from approximately $18.00 to $24.50. The
1996 Price/DCF Multiple for the Exploration Composite and Independents
Composite was 5.8 and 4.5, respectively, levels which correspond to a post-
Merger company stock price ranging from approximately $16.25 to $21.00. The
Unlevered 1995 DCF Multiple for the Exploration Composite and Independents
Composite was 8.8 and 7.2, respectively, levels which correspond to a post-
Merger company stock price ranging from approximately $19.00 to $23.75. The
Mcfe Value for the Exploration Composite and Independents Composite was 1.54
and 1.32, respectively, levels which correspond to a post-Merger company stock
price ranging from approximately $26.00 to $30.63, based on 1994 fiscal year-
end proved reserves, and ranging from $32.50 to $38.38, based on Plains'
interim reserves (as estimated by Plains' management) and Barrett's interim
reserves (as estimated on April 28, 1995 by Barrett's management and reviewed
and adjusted by Plains' management). The ratio of Total Capitalization to 1994
fiscal year-end SEC Value for the Exploration Composite and the Independents
Composite was 2.04 and 1.66, respectively, levels which correspond to a post-
Merger company stock price ranging from $19.75 to $24.75.
 
  PRO FORMA MERGER ANALYSIS. Goldman Sachs prepared pro forma analyses of the
financial impact of the Merger. Using earnings estimates for Plains and Barrett
prepared by their respective managements for the years 1995 and 1996, Goldman
Sachs estimated the effect of the Merger on the DCF per share of Plains Common
Stock and Barrett Common Stock. Goldman Sachs performed the analysis based on
the closing price of Plains Common Stock on April 28, 1995 (the "Plains Closing
Price") and the closing price of Barrett Common Stock on April 28, 1995 (the
"Barrett Closing Price"). The analysis indicated that the proposed transaction
would be dilutive to Plains' DCF by 18.4% in 1995 and accretive to Plains' DCF
by 9.0% in 1996, and accretive to Barrett's DCF by 56.2% in 1995 and accretive
to Barrett's DCF by 1.2% in 1996.
 
  CONTRIBUTION ANALYSIS. Goldman Sachs reviewed certain historical and
estimated future operating, financial and reserve information (including, among
other things, DCF, assets, proven reserves and production) for Plains and
Barrett, based on each of Plains and Barrett managements' financial forecasts
for their respective companies. Goldman Sachs analyzed the relative DCF, asset,
equity, reserve and production contributions of Plains and Barrett to the post-
Merger company on a pro forma basis, based on historical data and estimates for
1995 and 1996 provided to Goldman Sachs by Plains' and Barrett's managements
and before taking into account any of the possible benefits that may result
from the Merger. The analysis indicated that, based on the Plains Closing Price
and the Barrett Closing Price, the Plains shareholders would contribute 45% of
the outstanding common equity of the post-Merger company. The analysis also
indicated that in 1995 Plains would contribute 66% of combined DCF, while in
1996 Plains would contribute 49% of combined DCF. The analysis further
indicated that, as of March 31, 1995, Plains would have contributed 53% of
combined assets and as of April 28, 1995 would have contributed 59% of combined
interim proved reserves. In addition, the analysis indicated that in 1995
Plains would contribute 62% of combined natural gas production. Finally, the
analysis showed that Plains' last-five-years' reserve growth rate was negative
 
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<PAGE>
 
1.4% while Barrett's was 41.0%, and that Plains' last-five-years' production
growth rate was 16.3% while Barrett's was 39.8%, suggesting that, if current
trends continue, Barrett would over time provide an increasing percentage of
the reserves and production of the post-Merger company.
 
  The preparation of a fairness opinion is a complex process and is not
necessarily susceptible to partial analysis or summary description. Selecting
portions of the analyses or of the summary set forth above, without considering
the analyses as a whole, could create an incomplete view of the processes
underlying Goldman Sachs' opinion. In arriving at their fairness determination,
Goldman Sachs considered the results of all such analyses. No company or
transaction used in the above analyses as a comparison is identical to Plains
or Barrett or the contemplated transaction. The analyses were prepared solely
for purposes of Goldman Sachs' providing their opinion to the Plains Board of
Directors as to the fairness of the Exchange Ratio pursuant to the Merger
Agreement to the holders of the Plains Common Stock and do not purport to be
appraisals or necessarily reflect the prices at which businesses or securities
actually may be sold or may trade. Analyses based upon forecasts of future
results are not necessarily indicative of actual future results, which may be
significantly more or less favorable than suggested by such analyses. Because
such analyses are inherently subject to uncertainty, being based upon numerous
factors or events beyond the control of the parties or their respective
advisors, none of Plains, Barrett, Goldman Sachs or any other person assumes
responsibility if future results are materially different from those forecast.
 
  As described above, Goldman Sachs' opinion to the Board of Directors of
Plains was one of many factors taken into consideration by the Plains Board of
Directors on May 2, 1995 in making their determination to approve the Merger
Agreement.
 
  Goldman Sachs, as part of their investment banking business, is continually
engaged in the valuation of businesses and their securities in connection with
mergers and acquisitions, negotiated underwritings, competitive biddings,
secondary distributions of listed and unlisted securities, private placements,
and valuations for estate, corporate and other purposes. Plains selected
Goldman Sachs as its financial advisor because Goldman Sachs are an
internationally recognized investment banking firm and have substantial
experience in transactions similar to the Merger.
 
  Goldman Sachs provide a full range of financial, advisory and brokerage
services and in the course of their normal trading activities may from time to
time effect transactions and hold positions in the securities or options on
securities of Plains and/or Barrett for their own account and for the account
of customers. As of the date hereof, Goldman Sachs held for their own account
7,800 shares of Barrett Common Stock and no shares of Plains Common Stock.
 
  As previously noted, on December 7, 1993, Plains engaged Goldman Sachs as its
financial advisor to assist it in considering a broad range of strategic
options, including the consideration of a strategic merger. Under the
engagement, Plains agreed to pay Goldman Sachs a fee of $25,000, payable in
cash, per calendar quarter.
 
  On October 19, 1994, Goldman Sachs and Plains entered into a new engagement
letter (the "Engagement Letter") providing for the engagement of Goldman Sachs
as financial advisor to Plains with respect to an acquisition by Cross Timbers
or any tender offer, merger or other similar transaction with any other person,
rather than with respect to general advisory services. Pursuant to the terms of
the Engagement Letter, Plains has agreed to pay Goldman Sachs upon consummation
of the Merger a transaction fee, payable in cash, based on 0.85% of the value
of the Barrett Common Stock to be issued to the stockholders of Plains in the
Merger, against which is creditable a retainer fee of $250,000, already paid by
Plains. Plains has agreed to reimburse Goldman Sachs for their reasonable out-
of-pocket expenses, including attorney's fees, and to indemnify Goldman Sachs
against certain liabilities, including certain liabilities under the federal
securities laws.
 
  Pursuant to a letter agreement dated August 15, 1994 between Plains and
Batchelder, Plains agreed to pay Batchelder a retainer fee of $25,000 on
September 1, 1994 and an additional $25,000 at the beginning of each 90 day
period thereafter for a period of 18 months, provided, however, that the
aggregate retainer
 
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<PAGE>
 
pursuant to this sentence will be no more than $150,000. Pursuant to letter
agreements dated October 20, 1994 and February 27, 1995, Plains agreed that if
any transaction or series of transactions is consummated during the term of the
agreements whereby at least 30% of the common stock or assets of Plains are
exchanged for securities, cash or other assets, by whatever means, Plains will
pay Batchelder a fee equal to 1.5% of the amount by which the aggregate value
of the transaction exceeds $215 million, payable in cash upon closing of such
transaction. Equity, debt or other securities constituting a part of such
consideration that are traded on a national securities exchange will be valued
at the last closing price thereof prior to the date of the consummation or
closing of any such transaction. Notwithstanding the foregoing, Plains agreed
that, in any event, Batchelder's minimum fee, exclusive of its retainer, will
be $900,000.
 
MERGER CONSIDERATION
 
  Subject to certain provisions described herein with respect to shares of
Plains Common Stock owned by Plains, Barrett or any subsidiary of Plains or
Barrett, upon consummation of the Merger each issued and outstanding share of
Plains Common Stock, together with its associated Right, will be converted into
1.3 validly issued, fully paid and nonassessable shares of Barrett Common
Stock.
 
  Fractional shares of Barrett Common Stock will not be issued in the Merger.
Holders of Plains Common Stock otherwise entitled to a fractional share of
Barrett Common Stock will be paid cash in lieu of such fractional share
determined and paid as described in "--Fractional Shares" below.
 
  The Exchange Ratio was determined through negotiations between Barrett and
Plains, each of which was advised with respect to such negotiations by its
respective financial advisor. Based on the number of shares of Plains Common
Stock and the number of Plains Stock Options outstanding on the Plains Record
Date, a maximum of     shares of Barrett Common Stock may be issued in respect
of shares of Plains Common Stock in the Merger and     shares would be reserved
for issuance upon exercise and the terms of the related stock option plan of
Plains Stock Options which, pursuant to the Merger Agreement and the terms of
the related stock option plan, following the Merger will constitute options to
purchase Barrett Common Stock upon the terms set forth in such stock option
plans and the Merger Agreement.
 
  Any shares of Plains Common Stock owned by Plains or any of its subsidiaries
or by Barrett, Sub or any other subsidiary of Barrett will automatically be
cancelled at the Effective Time and will cease to exist and no capital stock of
Barrett or other consideration will be delivered in exchange therefor.
 
EFFECTIVE TIME OF THE MERGER
 
  The Merger will become effective upon the filing and acceptance of the
Certificate of Merger with the Secretary of State of the State of Delaware or
such later date as is specified in such Certificate. The filing of the
Certificate of Merger will occur as soon as practicable following the
satisfaction or waiver (where permissible) of the conditions set forth in the
Merger Agreement. See "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Conditions
to the Merger."
 
  THE MERGER AGREEMENT PROVIDES THAT, SUBJECT TO CERTAIN LIMITATIONS, THE
MERGER AGREEMENT MAY BE TERMINATED BY ONE OR ALL PARTIES AT ANY TIME PRIOR TO
THE EFFECTIVE TIME IF, AMONG OTHER REASONS, THE MERGER HAS NOT BEEN CONSUMMATED
ON OR BEFORE DECEMBER 31, 1995, NOTWITHSTANDING THE APPROVAL OF THE MERGER
AGREEMENT OR RELATED TRANSACTIONS BY THE STOCKHOLDERS OF PLAINS OR BARRETT. See
"CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Termination."
 
CONVERSIONS OF SHARES; PROCEDURES FOR EXCHANGE OF CERTIFICATES
 
  The conversion of Plains Common Stock, including the associated Rights, into
Barrett Common Stock will occur at the Effective Time. As soon as practicable
after the Effective Time, Barrett will deposit with The Bank of Boston, as
exchange agent (the "Exchange Agent"), for the benefit of the holders of
certificates which immediately prior to the Effective Time represented shares
of Plains Common Stock and associated
 
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<PAGE>
 
Rights (the "Certificates"), certificates representing the shares of Barrett
Common Stock (such shares of Barrett Common Stock, together with any dividends
or distributions with respect thereto payable as described below, being
hereinafter referred to as the "Exchange Fund") issuable in exchange for
outstanding shares of Plains Common Stock and associated Rights.
 
  As soon as practicable after the Effective Time, the Exchange Agent will mail
to each holder of record of a Certificate whose shares and associated Rights
are converted into shares of Barrett Common Stock a letter of transmittal
(which will specify that delivery will be effected, and risk of loss and title
to the Certificates will pass, only upon actual and proper delivery of the
Certificates to the Exchange Agent and will contain instructions for use in
effecting the surrender of the Certificates in exchange for certificates
representing shares of Barrett Common Stock and will be in such form and
contain such other provisions as Barrett and Plains may reasonably specify).
Upon surrender of a Certificate for cancellation to the Exchange Agent,
together with such letter of transmittal, duly executed, the holder of such
Certificate will be entitled to receive in exchange therefor a certificate
representing that number of whole shares of Barrett Common Stock which such
holder has the right to receive pursuant to the Merger, and the Certificate so
surrendered will be cancelled. Until surrendered as described above, each
Certificate will, at and after the Effective Time, be deemed to represent only
the right to receive, upon surrender of such Certificate, the certificate
representing the appropriate number of shares of Barrett Common Stock, and cash
in lieu of fractional shares and certain dividends and other distributions as
described below.
 
  PLAINS STOCKHOLDERS SHOULD NOT FORWARD PLAINS STOCK CERTIFICATES TO THE
EXCHANGE AGENT UNTIL THEY HAVE RECEIVED THE LETTER OF TRANSMITTAL.
 
  No dividends or other distributions that are declared on or after the
Effective Time on Barrett Common Stock or are payable to the holders of record
thereof on or after the Effective Time will be paid to persons entitled by
reason of the Merger to receive certificates representing Barrett Common Stock
until such persons surrender their Certificates, as described above, and no
cash payment in lieu of fractional shares will be paid to any such holder until
such holder of such Certificate surrenders such Certificate. Subject to the
effect of applicable law, there will be paid to the record holder of the
certificates representing such Barrett Common Stock (i) at the time of such
surrender or as promptly as practicable thereafter, the amount of any dividends
or other distributions theretofore paid with respect to whole shares of such
Barrett Common Stock and having a record date on or after the Effective Time
and a payment date prior to such surrender and (ii) at the appropriate payment
date or as promptly as practicable thereafter, the amount of dividends or other
distributions payable with respect to whole shares of Barrett Common Stock and
having a record date on or after the Effective Time but prior to surrender and
a payment date subsequent to surrender. In no event will the person entitled to
receive such dividends or other distributions be entitled to receive interest
on such dividends or other distributions. If any cash or certificate
representing shares of Barrett Common Stock is to be paid to or issued in a
name other than that in which the Certificate surrendered in exchange therefor
is registered, it will be a condition of such exchange that the Certificate so
surrendered be properly endorsed and otherwise in proper form for transfer and
that the person requesting such exchange pay to the Exchange Agent any transfer
or other taxes required by reason of the issuance of certificates for such
shares of Barrett Common Stock in a name other than that of the registered
holder of the Certificate surrendered, or establish to the satisfaction of the
Exchange Agent that such tax has been paid or is not applicable.
 
FRACTIONAL SHARES
 
  No certificates or scrip representing fractional shares of Barrett Common
Stock will be issued upon the surrender for exchange of Certificates pursuant
to the Merger Agreement, and no Barrett dividend or other distribution or stock
split or combination will relate to any fractional security, and such
fractional interests will not entitle the owner thereof to vote or to any
rights of a security holder of Barrett. In lieu of any such fractional
securities, each holder of shares of Plains Common Stock who would otherwise
have been entitled to receive a fraction of a share of Barrett Common Stock
(after taking into account all shares of Plains Common Stock then held of
record by such holder) will receive cash (without interest) in an amount equal
to
 
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<PAGE>
 
the product of such fractional part of a share of Plains Common Stock
multiplied by the Closing Price (as defined below). "Closing Price" means the
average of the midpoint of the daily high and low trading prices of Barrett
Common Stock, rounded to four decimal places, as reported under New York Stock
Exchange Composite Transactions Reports in The Wall Street Journal for each of
the first 20 consecutive Trading Days in the period commencing 25 Trading Days
prior to the date of the Effective Time. "Trading Day" means a day on which the
NYSE is open for trading.
 
  Any portion of the Exchange Fund which remains undistributed to the former
stockholders of Plains for one year after the Effective Time will be delivered
to Barrett, upon demand of Barrett, and any former stockholders of Plains who
have not theretofore complied with the provisions described above will
thereafter look only to Barrett for payment of their claim for Barrett Common
Stock, any cash in lieu of fractional shares of Barrett Common Stock and any
dividends or distributions with respect to Barrett Common Stock. None of
Barrett, Plains or the Surviving Corporation will be liable to any holder of
shares of Plains Common Stock (and associated Rights) for shares (or dividends
or distributions with respect thereto) or cash in lieu of fractional shares of
Barrett Common Stock delivered to a public official pursuant to any applicable
abandoned property, escheat or similar law.
 
CONDUCT OF BUSINESS PENDING MERGER
 
  Pursuant to the Merger Agreement, each of Barrett and Plains has agreed that
during the period from the date of the Merger Agreement through the Effective
Time (except as otherwise specifically required by the terms of the Merger
Agreement), it will, and it will cause its respective subsidiaries to, in all
material respects, carry on their respective businesses in the ordinary course
and consistent with past practice and, to the extent consistent therewith and
with the terms of the Merger Agreement, use all reasonable efforts to preserve
intact their current business organizations, keep available the services of
their current officers and employees and preserve their relationships with
customers, suppliers and others having business dealings with them to the end
that their goodwill and ongoing businesses will be unimpaired at the Effective
Time. The parties also have agreed to certain other covenants, as described
herein under "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Conduct of Business
Pending the Merger."
 
CONDITIONS TO THE CONSUMMATION OF THE MERGER
 
  The obligations of Barrett, Sub and Plains to consummate the Merger are
subject to various conditions, including, among other things, obtaining the
requisite stockholder approvals, the authorization for listing on the NYSE of
the shares of Barrett Common Stock issuable to Plains stockholders pursuant to
the Merger Agreement, the expiration or termination of the applicable waiting
period under the HSR Act, the effectiveness of the Registration Statement, and
the absence of any order or other legal restraint or prohibition preventing the
consummation of the Merger. The obligation of Plains to consummate the Merger
is subject to the fulfillment or waiver of various additional conditions,
including, among other things, that Barrett's Board of Directors will have
taken all necessary and appropriate actions to cause the number of directors
comprising its Board of Directors to be increased by four and the vacancies
thus created to be filled at the Effective Time by the Plains Designees. The
obligation of Barrett to consummate the Merger is subject to the fulfillment or
waiver of various additional conditions, including, among other things, that,
based on the advice of its independent accountants and such other advice as
Barrett deems relevant, Barrett shall have no reasonable basis for believing
that following the Merger the combination of Plains and Sub may not be
accounted for as a "pooling of interests" in accordance with generally accepted
accounting principles. See "--Governmental and Regulatory Approvals" and
"CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Conditions to the Merger."
 
GOVERNMENTAL AND REGULATORY APPROVALS
 
  The Merger is subject to the expiration or termination of the applicable
waiting period under the HSR Act. Certain aspects of the Merger will require
notification to, and filings with, certain securities and other authorities in
certain states, including jurisdictions where Barrett and Plains currently
operate.
 
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<PAGE>
 
  HSR ACT. Under the HSR Act and the rules promulgated thereunder by the
Federal Trade Commission (the "FTC"), the Merger may not be consummated until
notifications have been given and certain information has been furnished to the
FTC and the Antitrust Division of the Department of Justice (the "Antitrust
Division") and the applicable waiting period has expired or been terminated. It
is anticipated that Barrett and Plains will file notification and report forms
under the HSR Act with the FTC and the Antitrust Division on or about June 14,
1995. The waiting period under the HSR Act with respect to the Merger will
expire 30 calendar days after the filings unless extended pursuant to the HSR
Act. At any time before or after consummation of the Merger, notwithstanding
that the waiting period under the HSR Act has expired, the Antitrust Division
or the FTC could take such action under the antitrust laws as it deems
necessary or desirable in the public interest, including seeking to enjoin the
consummation of the Merger or seeking divestiture of substantial assets of
Barrett or Plains. At any time before or after the Effective Time, and
notwithstanding that the waiting period under the HSR Act has expired, any
state could take such action under the antitrust laws as it deems necessary or
desirable in the public interest. Such action could include seeking to enjoin
the consummation of the Merger or seeking divestiture of substantial assets of
Barrett or Plains. Private parties may also seek to take legal action under the
antitrust laws under certain circumstances.
 
  Based on information available to them, Barrett and Plains believe that the
Merger can be effected in compliance with federal and state antitrust laws.
However, there can be no assurance that a challenge to the consummation of the
Merger on antitrust grounds will not be made or that, if such a challenge were
made, Barrett and Plains would prevail or would not be required to accept
certain adverse conditions in order to consummate the Merger. The obligations
of Barrett and Plains to consummate the Merger are subject to the condition
that there shall be no preliminary or permanent injunction or other order by
any court or governmental or regulatory authority prohibiting the consummation
of the Merger. Each party has agreed to use reasonable efforts to defend any
such challenge or order and to seek to have any such order vacated or reversed.
 
CERTAIN FEDERAL INCOME TAX CONSEQUENCES
 
  The following is a general summary of the material U.S. federal income tax
consequences of the Merger to the holders of Plains Common Stock and Plains
Stock Options and is based upon current provisions of the Code, existing,
temporary and final regulations thereunder and the current administrative
rulings and court decisions all of which are subject to change (possibly on a
retroactive basis). The tax discussion set forth below is included for general
information only. It is not intended to be, nor should it be construed to be,
legal or tax advice to any particular holder of Plains Common Stock or Plains
Stock Options. No attempt has been made to comment on all U.S. federal income
tax consequences of the Merger that may be relevant to particular holders,
including holders that are subject to special tax rules such as dealers in
securities, mutual funds, insurance companies, tax-exempt entities and holders
who do not hold their shares as capital assets.
 
  No attempt has been made to address the U.S. federal income tax consequences
to a holder of Plains Common Stock or Plains Stock Options who, for U.S.
federal income tax purposes, is a non-resident alien individual, a foreign
corporation, a foreign partnership or a foreign estate or trust (a "Non-U.S.
Person"). A Non-U.S. Person may be subject to U.S. federal income tax
consequences as a result of the Merger that differ from those set out below. In
particular, a Non-U.S. Person that holds Plains Common Stock may be subject to
U.S. federal income and withholding tax under the Foreign Investment in Real
Property Tax Act ("FIRPTA") as a result of the Merger (even if the Merger
qualifies as a "reorganization" for U.S. federal income tax purposes) if such
Non-U.S. Person has held, directly or indirectly, more than five percent of the
Plains Common Stock at any time during the five-year period ending on the
Effective Time. Furthermore, a Non-U.S. Person may be subject to U.S. federal
income tax under FIRPTA upon a disposition of Barrett Common Stock received
pursuant to the Merger.
 
  HOLDERS OF PLAINS COMMON STOCK AND PLAINS STOCK OPTIONS ARE ADVISED AND
EXPECTED TO CONSULT WITH THEIR OWN LEGAL AND TAX ADVISERS REGARDING THE U.S.
FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER IN LIGHT OF THEIR PARTICULAR
CIRCUMSTANCES, AND ANY OTHER CONSEQUENCES TO THEM OF THE MERGER UNDER STATE,
LOCAL AND FOREIGN TAX LAWS.
 
                                       65
<PAGE>
 
  EXCHANGE OF PLAINS COMMON STOCK PURSUANT TO THE MERGER. Based on certain
assumptions, as well as representations received from Plains, Barrett and
certain stockholders of Plains, and subject to the discussion set out below,
the U.S. federal income tax consequences of the Merger will be as follows:
 
    (i) the Merger will constitute a "reorganization" within the meaning of
  Section 368(a) of the Code, and Plains, Barrett and Sub will each be a
  party to that reorganization within the meaning of Section 368(b) of the
  Code;
 
    (ii) no gain or loss will be recognized by Plains, Barrett or Sub as a
  result of the Merger;
 
    (iii) no gain or loss will be recognized by stockholders of Plains upon
  the conversion of their Plains Common Stock into shares of Barrett Common
  Stock pursuant to the Merger except with respect to cash, if any, received
  in lieu of fractional shares of Barrett Common Stock;
 
    (iv) the aggregate tax basis of the shares of Barrett Common Stock
  received in exchange for shares of Plains Common Stock pursuant to the
  Merger (including fractional shares of Barrett Common Stock for which cash
  is received) will be the same as the aggregate tax basis for such shares of
  Plains Common Stock at the time of the Merger;
 
    (v) the holding period for shares of Barrett Common Stock received in
  exchange for shares of Plains Common Stock pursuant to the Merger will
  include the holding period of such shares of Plains Common Stock, provided
  such shares of Plains Common Stock were held as capital assets by the
  holder at the Effective Time; and
 
    (vi) a stockholder of Plains who receives cash in lieu of a fractional
  share of Barrett Common Stock will recognize gain or loss equal to the
  difference, if any, between such holder's tax basis in the fractional share
  (as described in (iv) above) and the amount of cash received. Such gain or
  loss will be a capital gain or loss if the Plains Common Stock is held by
  such holder as a capital asset at the Effective Time.
 
The foregoing is based upon the assumption that the Merger is carried out in
accordance with the Merger Agreement and the assumption that the
representations and warranties contained in the Merger Agreement (including,
but not limited to, those in Sections 2.9 and 3.9 of the Merger Agreement) are
true and correct and will be true and correct as of the Effective Time as
though made as of the Effective Time.
 
  Dividends and other distributions paid with respect to the shares of Barrett
Common Stock issued upon exchange of the Plains Common Stock, as described
above under "--Conversion of Shares; Procedures for Exchange of Certificates,"
will generally be taxable as dividend income to the extent of Barrett's current
and accumulated earnings and profits.
 
  If the Merger is not treated as a reorganization for federal income tax
purposes, no gain or loss will be recognized by Barrett or Plains. However, a
stockholder of Plains will recognize gain or loss for U.S. federal income tax
purposes upon the conversion of Plains Common Stock into Barrett Common Stock
(and cash in lieu of fractional shares of Barrett Common Stock) pursuant to the
Merger equal to the difference between such holder's adjusted basis in the
Plains Common Stock exchanged and the fair market value of Barrett Common Stock
(plus the amount of cash received in lieu of fractional shares of Barrett
Common Stock) received by such holder in the Merger. Such gain or loss will be
capital gain or loss if the shares of Plains Common Stock were held as a
capital asset and will be long-term gain or loss if such shares had been held
for more than one year at the Effective Time.
 
  ASSUMPTION OF PLAINS STOCK OPTIONS PURSUANT TO THE MERGER. Holders of Plains
Stock Options that are assumed by Barrett as described below under "CERTAIN
PROVISIONS OF THE MERGER AGREEMENT--Plains Stock Options" generally will not
recognize income or gain for federal income tax purposes upon such assumption,
assuming the Merger is a tax-free reorganization as described above.
 
  A holder of an assumed Plains Stock Option will recognize ordinary
compensation income, and Barrett will be allowed a deduction for federal income
tax purposes, on the date such option is exercised in an amount equal to the
excess of the fair market value on such date of the Barrett Common Stock
acquired by exercise
 
                                       66
<PAGE>
 
of such option over the exercise price of such shares of Barrett Common Stock.
The tax basis of the Barrett Common Stock acquired by exercise of an assumed
Plains Stock Option will be its fair market value on the date of exercise of
such option and the holding period for purposes of determining whether a
subsequent sale of the Barrett Common Stock would result in the recognition of
short-term or long-term capital gain or loss will commence on the date of
transfer of the Barrett Common Stock to the holder of the option.
 
  Under current law, the tax rate imposed on long-term capital gains cannot
exceed 28%. The Code imposes limitations on the amount of capital loss which
can be deducted in a taxable year.
 
  If the holder of an assumed Plains Stock Option delivers shares of Barrett
Common Stock in payment of the exercise price of the Barrett Common Stock, such
holder will not recognize any taxable income by reason of such delivery. The
holder's basis and holding period for the number of shares of Barrett Common
Stock received equal to the number of shares delivered will be the same as the
shares delivered. The holder's basis for shares of Barrett Common Stock
received in excess of the number of shares delivered will equal the fair market
value of such shares of Barrett Common Stock used to determine the amount of
taxable compensation arising from the exercise of such option. The holding
period for such excess shares of Barrett Common Stock will commence on the date
the shares of Barrett Common Stock are transferred to the holder.
 
  Amounts described above as being treated as compensation income upon the
exercise of an assumed Plains Stock Option will be subject to tax at rates
applicable to ordinary income and will be subject to tax under the Federal
Insurance Contribution Act (i.e., FICA tax), subject to certain limitations in
the case of the old-age, survivors and disability insurance portion of the FICA
tax. The number of shares of Barrett Common Stock otherwise issuable to a
holder of an assumed Plains Stock Option which is exercised may be reduced by a
number of shares of Barrett Common Stock having a total fair market value equal
to the foregoing taxes and any other amounts required by law to be withheld.
 
ANTICIPATED ACCOUNTING TREATMENT
 
  The Merger is expected to qualify as a "pooling of interests" for accounting
and financial reporting purposes. Under this method of accounting, the recorded
assets and liabilities of Barrett and Plains will be carried forward to the
combined corporation at their recorded amounts; income of the combined
corporation will include income of Barrett and Plains for the entire fiscal
year in which the combination occurs; and the reported income of the separate
corporations for prior periods will be combined and restated as income of the
combined corporation.
 
  Following the Merger, Barrett will continue to follow the "full cost" method
of accounting for its oil and natural gas exploration and development
activities and will change its fiscal year end to December 31 from September
30. Plains currently follows the "successful efforts" method of accounting for
such activities and has a December 31 fiscal year end. See "UNAUDITED PRO FORMA
CONSOLIDATED CONDENSED FINANCIAL STATEMENTS."
 
TREATMENT OF PLAINS STOCK OPTIONS
 
  At the Effective Time, outstanding Plains Stock Options will become and
represent options to acquire a number of shares of Barrett Common Stock equal
to the number of shares of Plains Common Stock subject to such Plains Stock
Options times the Exchange Ratio at an exercise price per share of Barrett
Common Stock equal to the exercise price per share of Plains Common Stock
immediately prior to the Effective Time divided by the Exchange Ratio. See
"CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Plains Stock Options."
 
EMPLOYEE BENEFITS MATTERS
 
  Pursuant to the Merger Agreement, at the Effective Time, all employee
benefits plans and programs will terminate, subject to all applicable laws, and
all vested rights and benefits of such benefit plans and programs will be
distributed to the eligible recipients in accordance with the terms of such
plans of Plains and its
 
                                       67
<PAGE>
 
subsidiaries, except that, with respect to the qualified benefit plans, the
parties may elect prior to the Effective Time to freeze benefit accruals in
lieu of terminating the plans as of the Effective Time. To the extent that they
continue as employees of Barrett after the Merger, the officers and employees
of Plains and its subsidiaries will be provided by Barrett with employee
benefits under plans and programs which, in the aggregate, are no less
favorable than those provided pursuant to the plans and programs of Barrett and
its subsidiaries in effect on the date of the Merger Agreement. If Barrett or
any of its subsidiaries at any time provides benefits to retirees of Barrett or
any of its subsidiaries, retirees of Plains and its subsidiaries will be
provided benefits which, in the aggregate, are no less favorable than those
provided to retirees of Barrett and its subsidiaries. See "CERTAIN PROVISIONS
OF THE MERGER AGREEMENT--Employee Benefits."
 
INTERESTS OF CERTAIN PERSONS IN THE MERGER
 
  The Merger Agreement provides that from and after the Effective Time, Barrett
will indemnify and hold harmless all past and present officers and directors of
Plains and of its Subsidiaries to the full extent such persons may be
indemnified by Plains pursuant to Plains' Certificate of Incorporation and By-
laws for acts or omissions occurring at or prior to the Effective Time and will
advance reasonable litigation expenses incurred by such officers and directors
in connection with defending any action arising out of such acts or omissions.
In addition, Barrett will provide, or cause the Surviving Corporation to
provide, for a period of not less than six years from the Effective Time,
Plains' current directors and officers with an insurance and indemnification
policy that provides coverage for events occurring through the Effective Time
that is no less favorable than the existing policy or, if substantially
equivalent insurance coverage is unavailable, the best available coverage;
provided, however, that Barrett and the Surviving Corporation will not be
required to pay an annual premium for such insurance in excess of two times the
last annual premium paid by Plains prior to the date of the Merger Agreement
(which annual premium Plains has represented and warranted to have been $90,274
in the aggregate), but in such case will purchase as much coverage as possible
for such amount. See "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--
Indemnification; Directors and Officers Insurance."
 
  The Merger Agreement also provides that, after consultation with Barrett,
Plains will be permitted to offer and pay bonuses, in addition to any bonuses
or payments pursuant to any existing bonus or incentive plans of Plains, in an
aggregate amount up to $625,000, payable to (i) non-officer employees who
remain in the employ of Plains or its subsidiaries until a date set by Plains,
which date will be no earlier than the date three months after the Effective
Time or (ii) non-officer employees whose performance and dedication to Plains
or its subsidiaries merits, in the discretion of the Chief Executive Officer of
Plains, special compensation. Under the Merger Agreement, certain severance and
other arrangements also will continue to be honored and/or provided by Barrett.
See "CERTAIN PROVISIONS OF THE MERGER AGREEMENT--Stay Bonuses; Merit Bonuses;
Severance Policy."
 
  Pursuant to the Merger Agreement, shares of Plains Common Stock held by
executive officers and directors of Plains will be converted into the same
consideration as shares of Plains Common Stock held by other stockholders. At
the Effective Time, outstanding Plains Stock Options will become and represent
options to acquire a number of shares of Barrett Common Stock equal to the
number of shares of Plains Common Stock subject to such Plains Stock Options
times the Exchange Ratio at an exercise price per share of Barrett Common Stock
equal to the exercise price per share of Plains Common Stock immediately prior
to the Effective Time divided by the Exchange Ratio. See "CERTAIN PROVISIONS OF
THE MERGER AGREEMENT--Plains Stock Options."
 
  At the Effective Time, Barrett's Board of Directors will be increased from
nine to 13 members, and the directors of Barrett will elect the Plains
Designees to fill the newly created vacancies. The terms of all directors of
Barrett, including the Plains Designees, will expire at the next annual meeting
of stockholders of Barrett. Also, at the Effective Time, William J. Barrett
will continue as Chairman and Chief Executive Officer of Barrett, Paul M. Rady
will continue as President and Chief Operating Officer of Barrett, and William
F. Wallace, currently the President and Chief Operating Officer of Plains, will
become Vice Chairman of Barrett.
 
                                       68
<PAGE>
 
  Additional information relating to executive compensation and various benefit
arrangements of Plains is set forth in and incorporated herein by reference to
Plains' Annual Report on Form 10-K for the fiscal year ended December 31, 1994.
See "AVAILABLE INFORMATION" and "INCORPORATION OF CERTAIN DOCUMENTS BY
REFERENCE."
 
STOCK EXCHANGE LISTING
 
  It is a condition to the parties' obligations under the Merger Agreement that
the shares of Barrett Common Stock issuable pursuant to the Merger Agreement
shall have been approved for listing on the NYSE, subject to official notice of
issuance.
 
RESALE OF BARRETT COMMON STOCK
 
  The Barrett Common Stock to be issued pursuant to the Merger will be freely
transferable, except that shares issued to any Plains stockholder who may be
deemed to be an "affiliate" (as defined under the Securities Act and generally
including, without limitation, directors, certain executive officers and
beneficial owners of 10% or more of a class of capital stock) of Plains for
purposes of Rule 145 under the Securities Act will not be transferable except
in compliance with the Securities Act. This Joint Proxy Statement/Prospectus
does not cover resales of Barrett Common Stock received by any person who may
be deemed to be an affiliate of Plains.
 
  Pursuant to the Merger Agreement, Plains has agreed to use its reasonable
best efforts to cause each person who is an affiliate of Plains within the
meaning of Rule 145 under the Securities Act to deliver to Barrett on or prior
to the Effective Time a written agreement to the effect that such affiliate
will not sell, pledge, transfer or otherwise dispose of any shares of Barrett
Common Stock issued to such person pursuant to the Merger, except pursuant to
an effective registration statement or in compliance with Rule 145 or an
exemption from the registration requirements of the Securities Act, and that
such affiliate will not sell or in any other way reduce such affiliate's risk
relative to any shares of Barrett Common Stock received in the Merger until
such time as financial results (including combined sales and net income)
covering at least 30 days of post-Merger operations have been published, except
as permitted by published guidance from the Commission.
 
        UNAUDITED PRO FORMA CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
 
  The following unaudited pro forma consolidated condensed financial statements
reflect adjustments to the historical consolidated balance sheets and
statements of income of Barrett and Plains to give effect to the Merger, using
the pooling of interests method of accounting. The unaudited pro forma
consolidated condensed balance sheet at March 31, 1995, assumes the Merger was
consummated as of March 31, 1995 and the unaudited pro forma consolidated
condensed statements of income assume the Merger was consummated as of October
1, 1991.
 
  The following pro forma consolidated condensed financial statements have been
prepared from, and should be read in conjunction with, the historical
consolidated financial statements and notes thereto of Barrett and Plains that
are included in this Joint Proxy Statement/Prospectus. The pro forma
consolidated condensed statements of income are not necessarily indicative of
operating results that would have occurred had the Merger been consummated as
of October 1, 1991, nor are they indicative of future operating results of the
combined companies.
 
                                       69
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
           PRO FORMA CONSOLIDATED CONDENSED BALANCE SHEET (UNAUDITED)
 
                                 MARCH 31, 1995
 
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                       HISTORICAL             PRO FORMA
                                    -----------------  ------------------------
                                    BARRETT   PLAINS   ADJUSTMENTS CONSOLIDATED
                                    -------- --------  ----------- ------------
<S>                                 <C>      <C>       <C>         <C>
              ASSETS
Current assets:
  Cash and cash equivalents........ $ 11,047 $  2,001    $   --      $ 13,048
  Receivables......................   22,071    6,266        --        28,337
  Inventory, at lower of average
   cost or market..................      --       647        --           647
  Other current assets.............      212      622        --           834
                                    -------- --------    -------     --------
    Total current assets...........   33,330    9,536        --        42,866
Net property and equipment.........   98,360  145,529     28,615      272,504
Other assets.......................      150      --         --           150
                                    -------- --------    -------     --------
                                    $131,840 $155,065    $28,615     $315,520
                                    ======== ========    =======     ========
 LIABILITIES AND STOCKHOLDERS' EQ-
                UITY
Current liabilities:
  Accounts payable................. $  9,115 $  1,338    $   --      $ 10,453
  Due to oil and gas property
   owners..........................   15,440    1,052        --        16,492
  Accrued and other liabilities....    2,162    5,205        --         7,367
                                    -------- --------    -------     --------
    Total current liabilities......   26,717    7,595        --        34,312
                                    -------- --------    -------     --------
Other long-term liabilities........      --     1,023        --         1,023
                                    -------- --------    -------     --------
Post retirement benefits...........      --       952        --           952
                                    -------- --------    -------     --------
Long-term debt.....................   31,000   34,500        --        65,500
                                    -------- --------    -------     --------
Deferred income taxes..............      --    10,692     11,829       22,521
                                    -------- --------    -------     --------
Stockholders' equity:
  Preferred stock..................      --       --         --           --
  Common stock.....................      119       98         30          247
  Additional paid-in capital.......   59,132   20,383        (30)      79,485
  Retained earnings................   14,872   80,364     16,786      112,022
  Treasury stock, at cost..........      --      (542)       --          (542)
                                    -------- --------    -------     --------
    Total stockholders' equity.....   74,123  100,303     16,786      191,212
                                    -------- --------    -------     --------
                                    $131,840 $155,065    $28,615     $315,520
                                    ======== ========    =======     ========
</TABLE>
 
 See accompanying notes to unaudited pro forma consolidated condensed financial
                                   statements
 
                                       70
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
              PRO FORMA CONSOLIDATED CONDENSED STATEMENT OF INCOME
                                  (UNAUDITED)
 
                        SIX MONTHS ENDED MARCH 31, 1995
 
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                      HISTORICAL              PRO FORMA
                                    ---------------    ------------------------
                                    BARRETT PLAINS     ADJUSTMENTS CONSOLIDATED
                                    ------- -------    ----------- ------------
<S>                                 <C>     <C>        <C>         <C>
Revenues:
  Oil and gas production........... $10,343 $36,830      $   --      $47,173
  Trading revenues.................  18,520     --           --       18,520
  Revenue from gas gathering.......     442     --           --          442
  Interest income..................     205     --           --          205
  Other income.....................      41     --           --           41
                                    ------- -------      -------     -------
                                     29,551  36,830          --       66,381
Operating expenses:
  Lease operating expense..........   2,390  14,583(1)       --       16,973
  Cost of trading..................  17,869     --           --       17,869
  Depreciation, depletion and
   amortization....................   4,806  10,262         (454)     14,614
  General and administrative.......   2,983   3,892          417       7,292
  Exploration......................     --    2,601       (2,601)        --
  Interest expense.................     370   1,032          --        1,402
  Other expense, net...............     --       79          --           79
                                    ------- -------      -------     -------
                                     28,418  32,449       (2,638)     58,229
                                    ------- -------      -------     -------
Income before income taxes.........   1,133   4,381        2,638       8,152
Provision for income taxes.........      23   1,427        1,392       2,842
                                    ------- -------      -------     -------
Net income from continuing
 operations........................ $ 1,110 $ 2,954      $ 1,246     $ 5,310
                                    ======= =======      =======     =======
Shares outstanding.................  12,106   9,817        2,945      24,868
                                    ======= =======      =======     =======
Net income per share from
 continuing operations............. $   .09 $   .30                  $   .21
                                    ======= =======                  =======
</TABLE>
- --------
(1) Includes lease operating expense, production and property taxes,
    transportation and processing, net profit payments and trust payments.
 
 
 
 See accompanying notes to unaudited pro forma consolidated condensed financial
                                   statements
 
                                       71
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
              PRO FORMA CONSOLIDATED CONDENSED STATEMENT OF INCOME
                                  (UNAUDITED)
 
              YEARS ENDED SEPTEMBER 30, 1994 AND DECEMBER 31, 1994
 
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                     HISTORICAL               PRO FORMA
                                --------------------   ------------------------
                                 BARRETT    PLAINS     ADJUSTMENTS CONSOLIDATED
                                --------- ----------   ----------- ------------
                                (9/30/94) (12/31/94)
<S>                             <C>       <C>          <C>         <C>
Revenues:
  Oil and gas production....... $ 17,577   $ 61,693      $   --      $ 79,270
  Trading revenues.............   22,443        --           --        22,443
  Revenue from gas gathering...      252        --           --           252
  Interest income..............      891        --           --           891
  Other income.................       89        --           --            89
                                --------   --------      -------     --------
                                  41,252     61,693          --       102,945
Operating expenses:
  Lease operating expense......    3,535     24,694(1)       --        28,229
  Cost of trading..............   21,577        --           --        21,577
  Depreciation, depletion and
   amortization................    6,915     17,353       (1,599)      22,669
  General and administrative...    4,713      7,350          838       12,901
  Exploration..................      --       2,861       (2,861)         --
  Interest expense.............        6        762          --           768
  Other income.................      --        (563)         --          (563)
                                --------   --------      -------     --------
                                  36,746     52,457       (3,622)      85,581
                                --------   --------      -------     --------
Income before income taxes.....    4,506      9,236        3,622       17,364
Provision for income taxes.....       67      2,586        2,504        5,157
                                --------   --------      -------     --------
Net income from continuing
 operations.................... $  4,439   $  6,650      $ 1,118     $ 12,207
                                ========   ========      =======     ========
Shares outstanding.............   11,917      9,808        2,942       24,667
                                ========   ========      =======     ========
Net income per share from
 continuing operations......... $    .37   $    .68                  $    .49
                                ========   ========                  ========
</TABLE>
- --------
(1) Includes lease operating expense, production and property taxes,
    transportation and processing, net profit payments and trust payments.
 
 
 See accompanying notes to unaudited pro forma consolidated condensed financial
                                   statements
 
                                       72
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
              PRO FORMA CONSOLIDATED CONDENSED STATEMENT OF INCOME
                                  (UNAUDITED)
 
              YEARS ENDED SEPTEMBER 30, 1993 AND DECEMBER 31, 1993
 
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                      HISTORICAL               PRO FORMA
                                 --------------------   ------------------------
                                  BARRETT    PLAINS     ADJUSTMENTS CONSOLIDATED
                                 --------- ----------   ----------- ------------
                                 (9/30/93) (12/31/93)
<S>                              <C>       <C>          <C>         <C>
Revenues:
  Oil and gas production........  $14,976   $64,280      $    --      $ 79,256
  Trading revenues..............   26,357       --            --        26,357
  Revenue from gas gathering....      271       --            --           271
  Interest income...............      498       --            --           498
  Other income..................      584       --            --           584
                                  -------   -------      --------     --------
                                   42,686    64,280           --       106,966
Operating expenses:
  Lease operating expense.......    2,725    27,331(1)        --        30,056
  Cost of trading...............   25,343       --            --        25,343
  Depreciation, depletion and
   amortization.................    6,130    15,282        (1,686)      19,726
  General and administrative....    2,565     6,415         1,461       10,441
  Exploration...................      --      4,623        (4,623)         --
  Interest expense..............       13       643           --           656
  Other expense.................      --        219           --           219
  Property impairment...........      --      9,300        (9,300)         --
                                  -------   -------      --------     --------
                                   36,776    63,813       (14,148)      86,441
                                  -------   -------      --------     --------
Income before income taxes......    5,910       467        14,148       20,525
Provision for income taxes......      154        84         5,747        5,985
                                  -------   -------      --------     --------
Net income from continuing
 operations.....................  $ 5,756   $   383      $  8,401     $ 14,540
                                  =======   =======      ========     ========
Shares outstanding..............   10,908     9,797         2,939       23,644
                                  =======   =======      ========     ========
Net income per share from
 continuing operations..........  $   .53   $   .04                   $    .61
                                  =======   =======                   ========
</TABLE>
- --------
(1) Includes lease operating expense, production and property taxes,
    transportation and processing, net profit payments and trust payments.
 
 
 See accompanying notes to unaudited pro forma consolidated condensed financial
                                   statements
 
 
                                       73
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
              PRO FORMA CONSOLIDATED CONDENSED STATEMENT OF INCOME
                                  (UNAUDITED)
 
              YEARS ENDED SEPTEMBER 30, 1992 AND DECEMBER 31, 1992
 
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                       HISTORICAL               PRO FORMA
                                  --------------------   ------------------------
                                   BARRETT    PLAINS     ADJUSTMENTS CONSOLIDATED
                                  --------- ----------   ----------- ------------
                                  (9/30/92) (12/31/92)
<S>                               <C>       <C>          <C>         <C>
Revenues:
  Oil and gas production........   $ 6,626   $58,541       $   --      $65,167
  Trading revenues..............    16,726       --            --       16,726
  Revenue from gas gathering....       279       --            --          279
  Interest income...............       600       --            --          600
  Other income..................        54       --            --           54
                                   -------   -------       -------     -------
                                    24,285    58,541           --       82,826
Operating expenses:
  Lease operating expense.......     1,397    25,467(1)        --       26,864
  Cost of gas trading...........    16,601       --            --       16,601
  Depreciation, depletion and
   amortization.................     3,259    11,415          (476)     14,198
  General and administrative....     2,062     5,559         1,659       9,280
  Exploration...................       --      4,865        (4,865)        --
  Interest expense..............        26       690           --          716
  Other income..................       --       (203)          --         (203)
                                   -------   -------       -------     -------
                                    23,345    47,793        (3,682)     67,456
                                   -------   -------       -------     -------
Income before income taxes......       940    10,748         3,682      15,370
Provision for income taxes......        18     1,614         4,158       5,790
                                   -------   -------       -------     -------
Net income from continuing oper-
 ations.........................   $   922   $ 9,134       $  (476)    $ 9,580
                                   =======   =======       =======     =======
Shares outstanding..............     9,733     9,796         2,939      22,468
                                   =======   =======       =======     =======
Net income per share from con-
 tinuing operations.............   $   .09   $   .93                   $   .43
                                   =======   =======                   =======
</TABLE>
- --------
(1) Includes lease operating expense, production and property taxes,
    transportation and processing, net profit payments and trust payments.
 
 
 See accompanying notes to unaudited pro forma consolidated condensed financial
                                   statements
 
                                       74
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
    NOTES TO UNAUDITED PRO FORMA CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
 
1. PRO FORMA FINANCIAL STATEMENTS
 
  The basis of the unaudited pro forma consolidated condensed balance sheet
reflects the conversion of each outstanding share of Plains Common Stock as of
April 28, 1995 into 1.3 shares of Barrett Common Stock. This conversion results
in a reallocation of $30,000 between additional paid-in capital and common
stock. The unaudited pro forma consolidated condensed statements of income
reflect the conversion of the historical number of shares of Plains Common
Stock used in computing earnings per share into Barrett Common Stock and common
stock equivalents using the Exchange Ratio of 1.3. See "THE MERGER--Merger
Consideration." The actual number of shares of Barrett Common Stock to be
issued in the Merger will be determined by the actual number of shares of
Plains Common Stock then outstanding. The Merger Agreement obligates Barrett to
assume each Plains option outstanding at the Effective Time. See "THE MERGER--
Plains Stock Options." Based on the number of Plains Stock Options outstanding
on April 28, 1995, at the Effective Time a total of 643,317 shares of Barrett
Common Stock will be reserved for issuance under the assumed Plains Stock
Options.
 
2. PERIODS PRESENTED
 
  The pro forma annual income statements were prepared using Barrett's income
statement for the years ended September 30, 1994, 1993 and 1992 and Plains'
income statements for the years ended December 31, 1994, 1993 and 1992. The pro
forma income statement for the six months ended March 31, 1995 was prepared
using both Barrett's and Plains' income statements for the six months ended
March 31, 1995. As a result, Plains' income statement results for the three
months ended December 31, 1994 have been included in the pro forma combined
income statements twice. For the three months ended December 31, 1994, Plains'
historical revenues were $18,196,000 and its historical net earnings were
$1,714,000.
 
3. RECLASSIFICATIONS
 
  Certain reclassifications have been made to the historical consolidated
financial statements of Plains to conform with Barrett's presentation. There
were no material intercompany transactions between Barrett and Plains requiring
elimination.
 
4. PRO FORMA ADJUSTMENTS
 
  Barrett uses the full cost method of accounting (full cost) for oil and gas
producing activities whereas Plains uses the successful efforts method of
accounting (successful efforts). A major difference between the two methods is
that exploration costs are capitalized under full cost but expensed under
successful efforts. Additionally, the full cost property unit for depletion
purposes is on a county by county basis compared to a prospect or field basis
for successful efforts. The pro forma adjustments convert Plains' historical
data to the full cost method of accounting.
 
    a. Barrett Common Stock is increased by $30,000 and additional paid-in
  capital is decreased by $30,000 to adjust common stock par value for the
  number of shares of Barrett Common Stock to be issued to consummate the
  Merger.
 
    b. Property and equipment are increased for the adjustment required to
  convert the Plains' method of oil and gas accounting from successful
  efforts to full cost. The pro forma adjustment includes $19.3 million for
  capitalization of the exploration costs and $9.3 million for reversal of
  the property impairment, both of which were expensed under successful
  efforts. Accumulated depreciation, depletion and amortization is adjusted
  for differences between full cost and successful efforts.
 
                                       75
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
   NOTES TO UNAUDITED PRO FORMA CONSOLIDATED CONDENSED FINANCIAL STATEMENTS--
                                  (CONTINUED)
 
    c. Retained earnings and deferred income taxes payable adjustments
  reflect the cumulative income statement effect of Plains converting to full
  cost.
 
    d. Under full cost, exploration costs are capitalized rather than being
  expensed under successful efforts. Property impairment reported by Plains
  in 1993 is not reported as an expense for full cost because Plains'
  discounted future net revenues exceeded its net cost basis of properties.
 
    e. General and administrative expenses are increased for the portion that
  was previously classified as a component of exploration expense in Plains'
  historical financial statements.
 
    f. Depreciation, depletion and amortization expense is adjusted for
  differences between full cost and successful efforts.
 
    g. Provision for income taxes is adjusted for the effect on deferred tax
  amounts related to converting Plains' historical financial results from
  successful efforts to full cost.
 
5. MERGER COSTS
 
  The pro forma unaudited consolidated condensed financial statements do not
include estimated combined Merger expenses, which are not expected to exceed
$12,200,000. The expenses, which primarily consist of financial advisory fees,
outside legal, accounting and professional fees and one-time costs of
consolidating certain operational and administrative functions of the
companies, will be expensed in 1995. The estimated merger expenses include
severance payments to Barrett and Plains employees that will result from the
consolidation of certain operational and administrative functions. These
expenses are estimated to be approximately $4,700,000. The level of severance
payments is dependent upon organizational and employment decisions that will
not be finalized until after the Merger. Certain of the employees that are
expected to be terminated are covered by severance agreements. The pro forma
statements do not include any cost savings expected to occur as a result of the
Merger.
 
                                       76
<PAGE>
 
                        SECURITY OWNERSHIP OF MANAGEMENT
                         AND CERTAIN BENEFICIAL OWNERS
 
BARRETT
 
  The following table sets forth certain information regarding the beneficial
ownership of Barrett Common Stock as of June 13, 1995 by (i) each director of
Barrett, each executive officer of Barrett named under "Executive Compensation"
in Barrett's Proxy Statement dated February 9, 1995 relating to Barrett's
Annual Meeting of Stockholders held on March 16, 1995, all directors and
executive officers of Barrett as a group, each Plains Designee and each person
known by Barrett to be the beneficial owner of more than 5% of the Barrett
Common Stock and (ii) the beneficial ownership of Barrett Common Stock as of
June 13, 1995, after giving effect to the conversion of the 9,832,025 shares of
Plains Common Stock outstanding on that date into 12,781,633 shares of Barrett
Common Stock in the Merger and the conversion of an aggregate of 492,679 Plains
Stock Options outstanding on that date into stock options of Barrett pursuant
to the Merger Agreement (the "Transactions"), by each of the persons referred
to in clause (i) above.
 
<TABLE>
<CAPTION>
                                                   BENEFICIAL OWNERSHIP
                                                  OF BARRETT COMMON STOCK
                                           -------------------------------------
                                                                   PERCENT AFTER
                                                                   GIVING EFFECT
                                                                      TO THE
  NAME AND ADDRESS OF BENEFICIAL OWNER         SHARES      PERCENT TRANSACTIONS
  ------------------------------------     --------------- ------- -------------
<S>                                        <C>             <C>     <C>
William J. Barrett.......................    383,153(1)(7)   3.2        1.5
C. Robert Buford.........................    618,011(2)(7)   5.2        2.5
James M. Fitzgibbons.....................      6,000(3)(7)     *          *
Hennie L.J.M. Gieskes....................    893,714(3)(7)   7.5        3.6
Robert W. Howard.........................      8,563(3)(7)     *          *
J. Frank Keller..........................     68,954(3)(7)     *          *
Paul M. Rady.............................     38,999(3)(7)     *          *
A. Ralph Reed............................     72,572(4)(7)     *          *
James T. Rodgers.........................      5,500(3)(7)     *          *
Philippe S.E. Schreiber..................     20,077(3)(7)     *          *
All directors and executive officers as a
 group (12 persons)......................  2,133,693(5)     17.7        8.6
Derrill Cody(6)..........................              --    --           *
William W. Grant, III(6).................              --    --           *
William F. Wallace(6)....................              --    --           *
Harry S. Welch(6)........................              --    --           *
Zenith Drilling Corporation..............    602,230(2)      5.0        2.4
</TABLE>
- --------
 * Less than 1% of the outstanding shares of Barrett Common Stock.
(1) The number of shares indicated includes 138,129 shares owned by Louise K.
    Barrett, Mr. Barrett's wife, and 19,999 shares underlying options
    exercisable within the next 60 days. Mr. Barrett's business address is 1125
    Seventeenth Street, Suite 2400, Denver, Colorado 80202.
(2) C. Robert Buford is considered the beneficial owner of the 602,230 shares
    of which Zenith Drilling Corporation ("Zenith") is the record owner. These
    shares are included twice in the table. They are listed as being held
    beneficially by both Zenith and Mr. Buford. Mr. Buford owns approximately
    89% of the outstanding common stock of Zenith. The number of shares of
    Barrett Common Stock indicated for
 
                                       77
<PAGE>
 
    Mr. Buford also includes 10,000 shares that are owned by Aguilla
    Corporation, which is owned by Mr. Buford's wife and adult children. Mr.
    Buford disclaims beneficial ownership of the shares held by Aguilla
    Corporation pursuant to Rule 16a-1(a)(4) under the Exchange Act. The number
    of shares indicated also includes 4,500 shares underlying currently
    exercisable options. The business address for Mr. Buford and Zenith is 1861
    North Rock Road, Wichita, Kansas 67206.
(3) The number of shares indicated consists of or includes the following number
    of shares underlying currently exercisable options held by each of the
    following persons: James M. Fitzgibbons, 3,500; Hennie L.J.M. Gieskes,
    4,000; Robert W. Howard, 6,000; J. Frank Keller, 18,599; Paul M. Rady,
    8,999; James T. Rodgers, 5,000; and Philippe S.E. Schreiber, 12,500.
(4) The number of shares indicated includes 12,600 shares owned by Mary C.
    Reed, Mr. Reed's wife, and 43,200 shares underlying options exercisable
    within the next 60 days.
(5) The number of shares indicated includes the shares owned by Zenith that are
    beneficially owned by Mr. Buford as described in note (2) and the aggregate
    of 126,297 shares underlying the options described in notes (1), (2), (3)
    and (4).
(6) Messrs. Cody, Grant, Wallace and Welch are Plains Designees.
(7) Each person has agreed to vote his shares of Barrett Common Stock in favor
    of the approval of the Charter Amendment and the Stock Issuance.
 
PLAINS
 
  The following table sets forth certain information regarding the beneficial
ownership of Plains Common Stock as of June 13, 1995 by (i) each director of
Plains, each executive officer of Plains named in the Summary Compensation
Table of Plains' Annual Report on Form 10-K for the fiscal year ended December
31, 1994, all directors and executive officers of Plains as a group and each
person known by Plains to be the beneficial owner of more than 5% of the Plains
Common Stock and (ii) the beneficial ownership of Barrett Common Stock as of
June 13, 1995, after giving effect to the Transactions, by each of the persons
referred to in clause (i) above.
 
<TABLE>
<CAPTION>
                                                              BENEFICIAL OWNERSHIP OF
                                      BENEFICIAL OWNERSHIP     BARRETT COMMON STOCK
                                            OF PLAINS          AFTER  GIVING EFFECT
                                         COMMON STOCK(1)        TO THE TRANSACTIONS
                                      ----------------------- --------------------------
NAME AND ADDRESS OF BENEFICIAL OWNER    SHARES      PERCENT     SHARES        PERCENT
- ------------------------------------  ------------ ---------- ------------- ------------
<S>                                   <C>          <C>        <C>           <C>
Derrill Cody(2)................           6,200         *             8,060      **
William W. Grant, III(2).......          15,500         *            20,150      **
Eugene A. Lang, Jr. ...........          39,035(3)      *            50,746      **
James A. Miller(2).............          38,170(4)      *            49,621      **
Lee B. VanRamshorst............          39,837(5)      *            51,788      **
Robert W. Wagner...............          28,950(6)      *            37,635      **
William F. Wallace(2)..........          11,630(7)      *            15,119      **
Harry S. Welch(2)..............          10,000         *            13,000      **
Charles E. Wright(2)...........           5,254(8)      *             6,830      **
All executive officers and di-
 rectors as a group (12 per-
 sons).........................         268,267        2.7          348,747      1.4
State Farm Mutual Automobile
 Insurance Company
 and related entity(9).........         711,410        7.2          924,433      3.7
One State Farm Plaza
Bloomington, Illinois 61710
</TABLE>
- --------
 * Less than 1% of the outstanding shares of Plains Common Stock.
** Less than 1% of the outstanding shares of Barrett Common Stock after giving
   effect to the Transactions.
 
                                       78
<PAGE>
 
(1) For purposes of determining the numbers of shares beneficially owned by the
    named individuals and by all executive officers and directors as a group,
    with respect to any director or executive officer who held options to
    purchase shares of Plains Common Stock exercisable within 60 days of June
    13, 1995, it was assumed that such options had been exercised and the
    shares issued were outstanding. The following number of shares representing
    such unexercised options were added to the holdings of each of the
    following directors and officers: Mr. Cody, 6,000 shares; Mr. Grant, 8,000
    shares; Mr. Lang, 35,932 shares; Mr. Miller, 27,552 shares; Mr.
    VanRamshorst, 35,564 shares; Mr. Wagner, 27,462 shares; Mr. Wallace, 11,428
    shares; Mr. Welch, 8,000 shares; Mr. Wright, 3,000 shares; and all
    executive officers and directors as a group, 219,073 shares. The respective
    directors and executive officers have sole voting power and sole investment
    power over all shares reflected in the table and in this note, except as
    described in the notes to this table.
(2) Each person has agreed to vote his shares of Plains Common Stock in favor
    of the approval and adoption of the Merger Agreement and the Merger.
(3) Includes 1,000 shares as to which Mr. Lang has shared investment power and
    shared voting power and 2,103 shares as to which Mr. Lang has no investment
    power and sole voting power.
(4) Includes 85 shares owned by Mr. Miller's wife individually or as custodian
    for their child over which Mr. Miller disclaims beneficial ownership and
    over which he has neither investment nor voting power, 1,000 shares as to
    which Mr. Miller has shared investment power and shared voting power and
    4,533 shares as to which Mr. Miller has no investment power and sole voting
    power.
(5) Includes 200 shares owned by Mr. VanRamshorst's children over which Mr.
    VanRamshorst disclaims beneficial ownership and over which he has neither
    investment power nor voting power and 4,073 shares as to which Mr.
    VanRamshorst has no investment power and sole voting power.
(6) Includes 300 shares as to which Mr. Wagner has shared investment power and
    shared voting power and 1,043 shares as to which Mr. Wagner has no
    investment power and sole voting power.
(7) Includes 202 shares as to which Mr. Wallace has no investment power and
    sole voting power.
(8) Includes 254 shares owned by Mr. Wright's wife over which Mr. Wright
    disclaims beneficial ownership and over which he has neither investment nor
    voting power.
(9) According to its Schedule 13G dated January 24, 1995 filed with the
    Commission. The Schedule 13G states that State Farm Mutual Automobile
    Insurance Company ("State Farm") has sole voting and sole investment power
    with respect to 611,410 shares of Plains Common Stock, and State Farm Fire
    and Casualty Company has sole voting power and sole investment power with
    respect to 100,000 shares of Plains Common Stock. The table does not
    include shares of Barrett Common Stock that may be owned by State Farm
    prior to the Merger.
 
                    DESCRIPTION OF CAPITAL STOCK OF BARRETT
 
  The following statements are brief summaries of certain provisions relating
to Barrett's capital stock and are qualified in their entirety by reference to
the provisions of Barrett's Certificate of Incorporation, as amended (the
"Barrett Charter"), and By-Laws (the "Barrett By-laws"), which are included as
exhibits to the Registration Statement of which this Joint Proxy
Statement/Prospectus is a part.
 
  Barrett's authorized capital consists of 17,000,000 shares of Barrett Common
Stock and 1,000,000 shares of Preferred Stock, par value $.001 per share
("Preferred Stock"). As of May 22, 1995, there were 11,956,238 shares of
Barrett Common Stock outstanding. At the Barrett Special Meeting, holders of
shares of Barrett Common Stock will consider and vote upon, among other things,
the Charter Amendment, pursuant to which the number of authorized shares of
Barrett Common Stock will be increased from 17,000,000 shares to 35,000,000
shares.
 
  Dividends may be declared and paid on the Barrett Common Stock out of legally
available surplus. Such dividends may be paid in cash, property or shares of
Barrett Common Stock. The Barrett Board of Directors may set aside reserves out
of funds available for dividends for any purpose the Barrett Board of Directors
determines to be in Barrett's best interest.
 
                                       79
<PAGE>
 
  Each share of Barrett Common Stock is entitled to share equally in dividends
from sources legally available therefor when, as, and if declared by the
Barrett Board of Directors and, upon liquidation or dissolution of Barrett,
whether voluntary or involuntary, to share equally in the assets of Barrett
available for distribution to the holders of the Barrett Common Stock.
 
  Each holder of Barrett Common Stock is entitled to one vote per share for all
purposes. The holders of Barrett Common Stock have no preemptive rights and
there is no cumulative voting, redemption right or right of conversion with
respect to the Barrett Common Stock.
 
  All outstanding shares of Barrett Common Stock are, and all shares to be
issued by Barrett pursuant to the Merger Agreement will be, validly issued,
fully paid and nonassessable. The Barrett Board of Directors is authorized to
issue additional shares of Barrett Common Stock within the limits authorized by
the Barrett Charter, without stockholder action.
 
  No shares of Preferred Stock have been issued. However, the Board of
Directors of Barrett has the right to fix the rights, privileges and
preferences, including preference upon liquidation, of any class of Preferred
Stock to be issued in the future out of authorized but unissued shares of
Preferred Stock. The Barrett Board of Directors may issue these shares after
adopting and filing a certificate of designations with the Secretary of State
of the State of Delaware.
 
                     DESCRIPTION OF CAPITAL STOCK OF PLAINS
 
  The following statements are brief summaries of certain provisions relating
to Plains capital stock and are qualified in their entirety by reference to the
provisions of Plains' Restated Certificate of Incorporation, as amended (the
"Plains Charter"), and By-Laws (the "Plains By-laws"), which are incorporated
by reference as exhibits to the Registration Statement of which this Joint
Proxy Statement/Prospectus is a part.
 
  Plains' authorized capital consists of 20,000,000 shares of Plains Common
Stock and 1,000,000 shares of Preferred Stock, par value $.01 per share. As of
June 13, 1995, there were 9,832,025 shares of Plains Common Stock outstanding.
As of the date of this Joint Proxy Statement/Prospectus, no shares of Preferred
Stock are outstanding; however, a series of preferred stock of Plains,
denominated "Series A Junior Participating Preferred Stock," has been
established in connection with the Rights Agreement. See "--Rights Agreement."
 
  The Board of Directors of Plains has the right to fix the rights, privileges
and preferences, including preference upon liquidation, of any class or
preferred stock to be issued in the future out of authorized but unissued
shares of Preferred Stock. The Plains Board of Directors may issue these shares
after adopting and filing a certificate of designations with the Secretary of
State of the State of Delaware.
 
  Dividends may be declared and paid on the Plains Common Stock out of legally
available surplus. Such dividends may be paid in cash, property or shares of
Plains Common Stock. The Plains Board of Directors may set aside reserves out
of funds available for dividends for any purpose the Plains Board of Directors
determines to be in Plains' best interest.
 
  Each share of Plains Common Stock is entitled to share equally in dividends
from sources legally available therefor when, as, and if declared by the Plains
Board of Directors and, upon liquidation or dissolution of Plains, whether
voluntary or involuntary, to share equally in the assets of Plains available
for distribution to the holders of the Plains Common Stock.
 
  Each holder of Plains Common Stock is entitled to one vote per share for all
purposes. The holders of Plains Common Stock are not entitled to cumulative
voting in the election of directors. Moreover, the holders of Plains Common
Stock have no preemptive rights and there is no redemption right or right of
conversion with respect to the Plains Common Stock.
 
                                       80
<PAGE>
 
RIGHTS AGREEMENT
 
  Under the Rights Agreement, each outstanding share of Plains Common Stock has
one Right which entitles the stockholder, until the earlier of May 20, 1998 or
the redemption of the Rights, to buy one one-hundredth of a share of a new
series of preferred stock of Plains, denominated "Series A Junior Participating
Preferred Stock," at a price of $100 per one one-hundredth of a share, subject
to adjustment.
 
  The Rights Agreement provides that the Rights are represented by and traded
with the Plains Common Stock certificates and are not exercisable or
transferable apart from the Plains Common Stock until the earlier of (i) ten
business days (or such later date as may be determined by action of the Board
of Directors prior to such time as any person becomes an Acquiring Person (as
defined below)) after a public announcement that a person or group has acquired
beneficial ownership of 15% or more of the Plains Common Stock (such person or
group being called an "Acquiring Person" and such date of first public
announcement being called the "Stock Acquisition Date") or (ii) ten business
days after a person or group commences, or announces it intends to commence, a
tender or exchange offer, the consummation of which would give such person or
group 15% or more of the Plains Common Stock (the earlier of such days being
called the "Distribution Date"). Separate certificates for the Rights will be
mailed to holders of Plains Common Stock as of the Distribution Date, and
thereafter the separate Right certificates alone will evidence the Rights. The
Rights are listed for trading on the NYSE.
 
  The Plains' Series A Junior Participating Preferred Stock is a series of
preferred stock that is nonredeemable and may rank junior to other series of
Preferred Stock of Plains that may be issued in the future. Each share of
Series A Junior Participating Preferred Stock will be entitled to a minimum
preferential semi-annual dividend of $10 per share but will be entitled to an
aggregate dividend equal to 100 times the dividend declared per share of Plains
Common Stock. In the event of liquidation, each share of Series A Junior
Participating Preferred Stock will be entitled to a minimum preferential
liquidation payment for $10,000 per share but will be entitled to an aggregate
payment of 100 times the payment made per share of Plains Common Stock. Each
share of Series A Junior Participating Preferred Stock will have 100 votes,
voting together with the Plains Common Stock. Finally, in the event of any
merger, consolidation or other transaction in which shares of Plains Common
Stock are exchanged, each share of Series A Junior Participating Preferred
Stock will be entitled to receive 100 times the amount received per share of
Plains Common Stock. These rights are protected by customary antidilution
provisions. Because of the nature of the Series A Junior Participating
Preferred Stock's dividend, liquidation and voting rights, the value of the one
one-hundredth of a share of Series A Junior Participating Preferred Stock
purchasable upon exercise of each Right should approximate the value of one
share of Plains Common Stock.
 
  In the event that, on or after May 12, 1988, any person becomes the
beneficial owner of 15% or more of the Common Stock, the Rights will adjust so
that, assuming the Rights are then exercisable, each Right (other than Rights
held by any Acquiring Person) will entitle its holder to purchase, at the then
current price of the Right, that number of shares of Plains Common Stock
having, at the time of such transaction, a market value of two times the
exercise price of the Right.
 
  Furthermore, in the event that, on or after the Stock Acquisition Date,
Plains is acquired in a merger or other business combination and is not the
surviving corporation or the Plains Common Stock is changed or exchanged or 50%
or more of its assets or earning power is sold, each Right, assuming it is then
exercisable, will entitle its holder to purchase, at the then current exercise
price of the Right, that number of shares of Common Stock of the surviving
company or the company receiving the greatest portion of the assets or earning
power transferred, as the case may be, having, at the time of such transaction,
a market value of two times the exercise price of the Right.
 
  At any time prior to the close of business on the tenth business day
following the Stock Acquisition Date, Plains, at its option, may redeem the
Rights at a price of $.01 per Right (the "Redemption Price"); provided that if
the Board of Directors of Plains authorizes redemption of the Rights under
certain
 
                                       81
<PAGE>
 
circumstances, there must be at least one Continuing Director and such
authorization will require the approval of a majority of the Continuing
Directors then holding office. Immediately upon the authorization of the
redemption of the Rights by the Board of Directors of Plains, the Rights will
terminate and the only right of the holders of Rights will be to receive the
Redemption Price.
 
  "Continuing Director" means a director who (i) either (A) was a member of the
Board of Directors of Plains prior to May 20, 1988, or (B) subsequently became
a director of Plains and whose initial election or initial nomination for
election subsequent to such date was approved by a vote of a majority of the
Continuing Directors then on the Board of Directors of Plains, and (ii) is not
an Acquiring Person or an affiliate or associate of an Acquiring Person or a
representative of an Acquiring Person or any such affiliate or associate.
 
  The Rights will expire on May 20, 1998, unless earlier redeemed by Plains as
described above. Until a Right is exercised, the holder thereof will have no
rights as a stockholder of Plains, including without limitation, the right to
vote or to receive dividends.
 
  So long as the Rights are attached to the Plains Common Stock, Plains will
issue one Right with each new share of Plains Common Stock issued so that all
such shares will have attached Rights. No fractional shares will be issued,
other than fractional shares of Series A Junior Participating Preferred Stock
of Plains that are integral multiples of one one-hundredth of a share, and a
cash payment will be made in lieu thereof based on the market price of the
preferred stock or Plains Common Stock on the last trading day prior to the
date of exercise.
 
  The Board of Directors of Plains may delay the distribution of Rights
Certificates if a tender or exchange offer has been announced or commenced so
long as there is no Acquiring Person.
 
  The Board of Directors of Plains may amend the Plains Rights Agreement. After
the Distribution Date, however, the Board of Directors of Plains may amend the
Plains Rights Agreement only to cure any ambiguity, to cure any defective or
inconsistent provisions, to make changes which do not adversely affect the
interest of the holders of the Rights (other than an Acquiring Person or an
affiliate or associate of an Acquiring Person) or to shorten or lengthen any
time period under the Plains Rights Agreement; provided that no amendment to
adjust the time period governing redemption may be made at any time when the
Rights are not redeemable. In addition, no supplement or amendment may be made
which changes the Redemption Price, the final expiration date, the purchase
price or the number of share of Series A Junior Participating Preferred Stock
for which a Right is exercisable, unless at the time of such supplement or
amendment there is no Acquiring Person and such supplement or amendment does
not adversely affect the interests of the holders of Rights certificates (other
than an Acquiring Person or an affiliate or associate of an Acquiring Person).
 
  The Rights Agreement was amended as of May 2, 1995 to provide that Barrett,
Sub and their affiliates or associates will not become an Acquiring Person by
virtue of the execution and delivery of the Merger Agreement or the
consummation of the Merger and the other transactions contemplated thereby and
that the acquisition of beneficial ownership of Plains Common Stock pursuant to
the Merger Agreement will not give rise to a Distribution Date or a Stock
Acquisition Date or trigger the exercisability of the Rights. Subject to
certain provisions described herein with respect to shares of Plains Common
Stock owned by Plains, Barrett or any subsidiary of Plains or Barrett, upon
consummation of the Merger each issued and outstanding share of Plains Common
Stock, together with its associated Right, will be converted into 1.3 validly
issued, fully paid and nonassessable shares of Barrett Common Stock. See "THE
MERGER--Merger Consideration."
 
                       COMPARISON OF RIGHTS OF HOLDERS OF
                  PLAINS COMMON STOCK AND BARRETT COMMON STOCK
 
GENERAL
 
  The rights of the holders of Plains Common Stock are currently governed by
the Plains Charter, the Plains By-laws and the laws of Delaware, including the
DGCL. If the Merger is consummated, holders of Plains Common Stock will become
stockholders of Barrett, and the rights of such former Plains stockholders will
thereafter be governed by the Barrett Charter, the Barrett By-laws and the laws
of Delaware, including
 
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the DGCL. The following summary, which does not purport to be a complete
statement of the differences between the rights of the stockholders of Barrett
and the stockholders of Plains, sets forth certain differences between the
Barrett Charter and the Plains Charter and the Barrett By-laws and the Plains
By-laws. This summary is qualified in its entirety by reference to the full
text of each of such documents and the applicable Delaware statutes.
 
VOTING RIGHTS
 
  Section 212 of the DGCL provides that unless otherwise provided in the
certificate of incorporation, each stockholder is entitled to one vote for each
share of capital stock held by such stockholder.
 
  The Plains By-laws provide that each holder of Plains Common Stock is
entitled to one vote for each share held by such holder on each matter upon
which holders of Plains Common Stock are entitled or afforded the opportunity
to vote. Except as otherwise provided in the Plains Charter, the Plains By-laws
or the DGCL, corporate action taken by vote of stockholders must be authorized
by the vote of the holders of a majority of the outstanding shares of all
classes of stock entitled to vote thereon present in person or by proxy at the
meeting. The Barrett Charter provides that each stockholder of record of
Barrett Common Stock is entitled to one vote for every share of such stock held
by such stockholder. Except as otherwise provided in the Barrett Charter, the
Barrett By-laws or the DGCL, whenever any corporate action is to be taken by
vote of the stockholders of Barrett, it must be authorized by a majority of the
votes cast at a meeting of stockholders by the holders of shares entitled to
vote thereon.
 
CLASSIFIED BOARD OF DIRECTORS
 
  Section 141(d) of the DGCL provides that a corporation may have a classified
board of directors providing for up to three classes of directors each having a
term of up to three years, and newly elected directors selected by the board of
directors may serve to the expiration of the term of the class to which they
are named.
 
  The Plains Charter and By-laws provide that Plains' Board is divided into
three classes of directors, each with a term of three years and consisting of a
number of directors as nearly equal in number as possible. Neither the Barrett
Charter nor the Barrett By-laws provide for a classified board of directors.
 
NUMBER OF DIRECTORS
 
  The number of directors of a Delaware corporation is fixed by, or in the
manner provided in, the by-laws unless such number is changed by action of the
majority of the directors. Under Section 141(b) of the DGCL, a director need
not be a stockholder to be qualified unless so required by the charter or by-
laws.
 
  The Plains Charter and By-laws provide that the number of directors may be
fixed from time to time by resolution of the Board of Directors of Plains
adopted by a majority of the Board, but in no case may the Plains Board consist
of fewer than five nor more than eleven members. The number of directors of
Plains is currently fixed at six. The Plains By-laws also provide that
directors whose term of office has expired are elected at the annual meeting of
stockholders by written ballot. The Barrett By-laws provide that the number of
directors will be determined by the Board of Directors of Barrett, but in no
case may the Board consist of fewer than three nor more than 13, unless such
change is approved in the manner provided in the Barrett By-laws. The number of
directors of Barrett is currently fixed at nine (and will be increased to 13 in
connection with the consummation of the Merger). Directors are elected at each
annual meeting of stockholders or at a special meeting of the stockholders. The
Barrett Charter states that elections of directors are not required to be by
written ballot unless the Barrett By-laws otherwise provide.
 
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BOARD OF DIRECTORS VACANCIES
 
  Section 223 of the DGCL provides that, unless otherwise provided in the
certificate of incorporation or by-laws, vacancies, including those due to
removal without cause, and newly created directorships may be filled by
majority vote of the directors then in office, even if the number of directors
then in office is less than a quorum.
 
  The Plains Charter provides that any vacancies (including newly created
directorships) may be filled by a majority vote of the directors then in
office, though less than a quorum, or by a sole remaining director. Any such
director chosen will hold office for the remainder of the term of such
director's predecessor. The Barrett By-laws provide that any vacancies
(including newly created directorships) may be filled by a majority vote of the
directors then in office, though less than a quorum, or by a sole remaining
director. Any such director will hold office until the next annual election.
 
REMOVAL OF DIRECTORS
 
  Section 141(k) of the DGCL provides that any director may be removed, with or
without cause, by a majority of the shares then entitled to vote at an election
of directors, except that unless the certificate of incorporation provides
otherwise in the case of a corporation with a classified board of directors,
such as Plains, a director may be removed only for cause.
 
  The Plains Charter and By-laws provide that any director may be removed from
office, only for cause, by the affirmative vote of the holders of at least a
majority of the total votes of all shares of stock entitled to vote in an
election of directors. The Barrett By-laws provide that any director may be
removed, with or without cause, by the holders of a majority of the shares then
entitled to vote at a meeting of stockholders.
 
QUORUM OF STOCKHOLDERS
 
  Both the Plains By-laws and the Barrett By-laws provide that the holders of a
majority of the shares of the outstanding stock entitled to vote, in person or
by proxy, constitutes a quorum at any meeting of the stockholders for the
transaction of business.
 
CALL OF SPECIAL STOCKHOLDER MEETINGS
 
  Under Section 211(d) of the DGCL, special meetings of stockholders may be
called by the board of directors or by such other person or persons authorized
to do so by the corporation's certificate of incorporation or by-laws.
 
  The Plains Charter provides that special meetings of the stockholders may be
called by the Chairman of the Board or the President of Plains and must be
called by the President or Secretary upon written application by at least three
directors then holding office. The Barrett By-laws provide that special
meetings of the stockholders may be called by the President or by the Barrett
Board of Directors.
 
STOCKHOLDERS' ACTION WITHOUT A MEETING
 
  Section 228 of the DGCL provides that, unless the certificate of
incorporation provides otherwise, stockholders may take any action without a
meeting by written consent signed by the holders of outstanding stock having
not less than the minimum number of votes that would be necessary to authorize
or take such action at a meeting at which all shares entitled to vote thereon
were present and voted. Prompt notice of the taking of any action by less than
unanimous consent must be given to stockholders who did not consent to such
action.
 
  The Plains Charter provides that any action that may be taken at an annual or
special meeting may be taken without a meeting only by written unanimous
consent of the stockholders. The Barrett By-laws contain a provision similar to
the provision of the DGCL described above.
 
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<PAGE>
 
AMENDMENTS TO CHARTER
 
  Under Section 242 of the DGCL, a corporation can amend its certificate of
incorporation in any respect; provided that the amendment contains only
provisions which would have been lawful in the original certificate of
incorporation. The DGCL provides that an amendment may be authorized by the
adoption of a resolution setting forth the amendment by the board of directors
followed by a majority vote of shares entitled to vote thereon. The DGCL also
provides for approval by vote of the holders of a majority of outstanding
shares of a particular class of stock in certain circumstances, including an
amendment which would increase the aggregate number of authorized shares of
such class.
 
PREEMPTIVE RIGHTS
 
  Neither Delaware law nor the Plains Charter or Plains By-laws provide
preemptive rights to the holders of capital stock. The Barrett Charter states
that no stockholders of Barrett shall have any preemptive rights.
 
DERIVATIVE ACTIONS
 
  Derivative actions may be brought in Delaware by a stockholder on behalf of,
and for the benefit of, the corporation. Section 327 of the DGCL provides that
a stockholder must aver in the complaint that he was a stockholder of the
corporation at the time of the transaction of which he complains.
 
DIVIDENDS
 
  Subject to any restrictions in a corporation's certificate of incorporation,
Section 170 of the DGCL generally provides that the directors of a corporation
may declare and pay dividends out of surplus (defined as the excess if any, of
the net assets over stated capital) or, when no surplus exists, out of net
profits for the fiscal year in which the dividend is declared and/or the
preceding fiscal year. Dividends may not be paid out of net profits if the
stated capital of the corporation is less than the aggregate amount of stated
capital represented by the issued and outstanding stock of all classes having a
preference upon the distribution of assets.
 
ISSUANCE OF RIGHTS OR OPTIONS TO PURCHASE SHARES TO DIRECTORS, OFFICERS AND
EMPLOYEES
 
  Under Section 157 of the DGCL, a Delaware corporation is permitted, either in
its certificate of incorporation or by resolution of the board of directors, to
create rights or options entitling the holders thereof to purchase from the
corporation any shares of its capital stock of any class or classes. In the
absence of actual fraud in the transaction, the judgment of the directors as to
the consideration for the issuance of such rights or options and the
sufficiency thereof shall be conclusive.
 
LIMITATIONS ON DIRECTORS' LIABILITY
 
  Section 102(b)(7) of the DGCL permits a corporation to include a provision in
its certificate of incorporation eliminating or limiting the personal liability
of a director to the corporation or its stockholders for damages for breach of
the director's fiduciary duty subject to certain limitations. The Plains
Charter and the Barrett Charter include such a provision, as set forth below,
to the maximum extent permitted by law.
 
  The Plains Charter provides that a director will not be personally liable to
the corporation or its stockholders for monetary damages for breach of
fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or
a knowing violation of law, (iii) for the unlawful payment of dividends or
unlawful stock repurchases under Section 174 of the DGCL, or (iv) for any
transaction from which the director derived an improper personal benefit. The
Barrett Charter provides that the personal liability of each director of the
corporation shall be eliminated and limited to the full extent permitted by the
laws of the State of Delaware.
 
 
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<PAGE>
 
  While these provisions provide directors with protection from liability for
monetary damages for breaches of their duty of care, they do not eliminate such
duty. Accordingly, these provisions will have no effect on the availability of
equitable remedies such as an injunction or rescission based on a director's
breach of his or her duty of care. The provisions described above apply to an
officer of the corporation only if he or she is a director of the corporation
and is acting in his or her capacity as director, and do not apply to officers
of the corporation who are not directors.
 
BUSINESS COMBINATION PROVISIONS
 
  In 1988, Delaware enacted a statute designed to provide Delaware corporations
with limited protection against hostile takeovers. The takeover statute, which
is codified in Section 203 of the DGCL ("Section 203"), is intended to
discourage certain takeover practices by impeding the ability of a hostile
acquiror to engage in certain transactions with the target company.
 
  In general, Section 203 provides that a person or entity that owns 15% or
more of the outstanding voting stock of a Delaware corporation (an "Interested
Stockholder") may not consummate a merger or other business combination
transaction with such corporation at any time during the three-year period
following the date such person or entity became an Interested Stockholder,
unless (i) prior to the date a person became an Interested Stockholder, the
board of directors approved either the business combination or the transaction
which resulted in the stockholder becoming an Interested Stockholder, or (ii)
upon consummation of the transaction that resulted in the stockholder becoming
an Interested Stockholder, the Interested Stockholder owned at least 85% of the
corporation's outstanding voting stock at the time the transaction commenced,
with the number of shares outstanding calculated without regard to those shares
owned by the corporation's directors who are also officers or by certain
employee stock plans, or (iii) on or subsequent to the date a person became an
Interested Stockholder, the business combination with an Interested Stockholder
is approved by the board of directors and by a two-thirds vote of the
outstanding voting stock not owned by the Interested Stockholder.
 
  The Plains Charter adds to the requirements of the DGCL and provides that no
business combination with an "Interested Related Party" (defined as a
stockholder who beneficially owns 10% or more of the outstanding capital stock
of the corporation entitled to vote in elections of directors) may occur unless
the business combination is approved by the affirmative vote of the number of
outstanding shares equal to the sum of (i) the number of shares of voting stock
beneficially owned by the Interested Related Party and (ii) 90% of the
remaining number of outstanding shares of such voting stock that are not
beneficially owned by any Interested Related Party. The Plains Charter provides
further that such approval is not required for any business combination if (i)
it is approved by a resolution adopted by at least 75% of those directors who
are not related parties or (ii) if the value of the consideration to be
received by Plains' stockholders in such business combination is not less than
certain specified amounts and certain other conditions are met. Barrett's By-
laws provide that an "interested person" (defined as a person who becomes the
beneficial owner of more than 15% of the outstanding shares of voting stock)
may not acquire additional shares of voting stock except as part of (a) the
transaction that results in that interested person first becoming an interested
person, or (b) pursuant to a business combination approved in accordance with
the Barrett Charter as described above.
 
INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
  Section 145 of the DGCL permits a corporation to indemnify officers,
directors, employees and agents for actions taken in good faith and in a manner
they reasonably believed to be in, or not opposed to, the best interests of the
corporation, and with respect to any criminal action, which they had no
reasonable cause to believe was unlawful. The DGCL also provides that a
corporation may advance expenses of defense (upon receipt of a written
undertaking to reimburse the corporation if indemnification is not appropriate)
and must reimburse a successful defendant for expenses, including attorney's
fees, actually and reasonably incurred, and permit a corporation to purchase
and maintain liability insurance for its directors and officers. The DGCL
further provides that indemnification may not be made for any claim, issue or
matter as to which a person has been adjudged by a court of competent
jurisdiction, after exhaustion of all appeals therefrom, to
 
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<PAGE>
 
be liable to the corporation, except only to the extent a court determines that
the person is entitled to indemnity for such expenses that such court deems
proper.
 
  The Plains Charter provides that any person who was or is a party or is
threatened to be made a party to any threatened, pending or completed action,
suit or proceeding, whether civil, criminal, administrative or investigative
(other than an action by or in the right of the corporation) by reason of the
fact that he is or was a director, officer, employee or agent of the
corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, shall be indemnified by the corporation
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful. The termination of any
action, suit or proceeding by judgment, order, settlement, conviction, or upon
a plea of nolo contendere or its equivalent, shall not, of itself, create a
presumption that the person did not act in good faith and in a manner which he
reasonably believed to be in or not opposed to the best interests of the
corporation, and, with respect to any criminal action or proceeding, had
reasonable cause to believe that his conduct was unlawful. The Plains Charter
provides further that the corporation shall indemnify any person who was or is
a party or is threatened to be made a party to any threatened, pending or
completed action or suit by or in the right of the corporation to procure a
judgment in its favor by reason of the fact that he is or was a director,
officer, employee or agent of the corporation, or is or was serving at the
request of the corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise against
expenses (including attorneys' fees) actually and reasonably incurred by him
and in connection with the defense or settlement of such action or suit if he
acted in good faith and in a manner he reasonably believed to be in or not
opposed to the best interests of the corporation. No indemnification shall be
made in respect of any claim, issue or matter as to which such person shall
have been adjudged to be liable to the corporation, however, unless and only to
the extent that the court of Chancery of Delaware or the court in which such
action or suit was brought shall determine upon application that, despite the
adjudication of liability but in view of all the circumstances of the case,
such person is fairly and reasonably entitled to indemnity for such expense
which the Court of Chancery of Delaware or such other court shall deem proper.
The rights to indemnification and the advancement of expenses conferred by the
Plains Charter are not exclusive of any other right to which a person seeking
indemnification may be entitled under any by-law, agreement, vote of
stockholders or disinterested directors or otherwise. Plains is authorized to
purchase and maintain, and Plains does maintain, insurance on behalf of its
directors, officers, employees and agents. The Barrett By-laws currently
provide for mandatory indemnification of directors, officer and employees and
advancement of indemnified expenses to the full extent permitted by the DGCL,
the common law or any statutory provision other than the DGCL.
 
DISSENTERS' RIGHTS OF APPRAISAL
 
  The DGCL generally entitles a stockholder to exercise appraisal rights upon a
merger or consolidation of the corporation effected pursuant to the DGCL if the
holder complies with the requirements of Section 262 of the DGCL. Appraisal
rights are available under Section 262 of the DGCL if holders of shares in a
constituent company, which shares are listed on a national securities exchange
(as the Plains Common Stock is), are required by the terms of the merger to
accept consideration other than shares of stock of the surviving corporation,
shares of stock of any corporation listed on a national securities exchange,
designated as a national market system security by the National Association of
Securities Dealers, Inc. or held of record by more than 2,000 stockholders, or
cash in lieu of fractional shares.
 
  As holders of Plains Common Stock will receive only Barrett Common Stock,
which is listed on the NYSE, and cash in lieu of fractional shares under the
terms of the Merger Agreement, they are not entitled to appraisal rights under
the DGCL. Holders of Barrett Common Stock will not be entitled to appraisal
rights under the DGCL. See "THE SPECIAL MEETINGS--Appraisal Rights."
 
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<PAGE>
 
LISTING
 
  Both the Plains Common Stock and the Barrett Common Stock are listed on the
NYSE.
 
                   CERTAIN PROVISIONS OF THE MERGER AGREEMENT
 
  The following is a summary of certain provisions of the Merger Agreement,
which appears as Annex I to this Joint Proxy Statement/Prospectus and is
incorporated herein by reference. The following summary includes the material
terms of such agreement but is not necessarily complete and is qualified in its
entirety by reference to the Merger Agreement.
 
THE MERGER
 
  The Merger Agreement provides that, subject to the terms and conditions
contained therein, including the approval and adoption of the Merger Agreement
by the holders of Plains Common Stock and the approval of the Charter Amendment
and the Stock Issuance by the holders of Barrett Common Stock, as described in
this Joint Proxy Statement/Prospectus, Sub will be merged with and into Plains,
and Plains will continue as the Surviving Corporation.
 
  If the conditions to the Merger are satisfied or waived (where permissible),
the parties will file with the Secretary of State of the State of Delaware a
duly executed Certificate of Merger, and the Merger will become effective at
the Effective Time, which will occur upon the filing and acceptance thereof or
at such date thereafter as is provided in the Certificate of Merger.
 
  Pursuant to the Merger Agreement, as of the Effective Time, by virtue of the
Merger and without any action on the part of any stockholder of Plains, all
shares of Plains Common Stock, and the associated Rights, that are held in the
treasury of Plains or by any wholly owned subsidiary of Plains and any shares
of Plains Common Stock (and associated Rights) owned by Barrett, Sub or any
other wholly owned subsidiary of Barrett will be cancelled and no capital stock
of Barrett or other consideration will be delivered in exchange therefor.
 
  Each issued and outstanding share of capital stock of Sub will be converted
into and become one validly issued, fully paid and nonassessable share of
Common Stock, par value $.01 per share, of the Surviving Corporation.
 
  Each share of Plains Common Stock (together with its associated Right) issued
and outstanding immediately prior to the Effective Time (other than shares (and
associated Rights) to be cancelled) will be converted into 1.3 validly issued,
fully paid and nonassessable shares of Barrett Common Stock. All such shares of
Plains Common Stock (and associated Rights), when so converted, will no longer
be outstanding and will automatically be cancelled and retired and each holder
of a Certificate representing any such shares (and associated Rights) will
cease to have any rights with respect thereto, except the right to receive
certain dividends and other distributions and shares of Barrett Common Stock
and any cash, without interest, in lieu of fractional shares to be issued or
paid in consideration therefor upon the surrender of such Certificate.
 
  No certificates or scrip representing fractional shares of Barrett Common
Stock will be issued upon the surrender for exchange of Certificates, and no
Barrett dividend or other distribution or stock split or combination will
relate to any fractional security, and such fractional interests will not
entitle the owner thereof to vote or to any rights of a security holder of
Barrett. In lieu of any such fractional securities, each holder of shares of
Plains Common Stock who would otherwise have been entitled to receive a
fraction of a share of Barrett Common Stock (after taking into account all
shares of Plains Common Stock then held of record by such holder) will receive
cash (without interest) in an amount equal to the product of such fractional
part of a share of Plains Common Stock multiplied by the Closing Price.
 
 
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REPRESENTATIONS AND WARRANTIES
 
  The Merger Agreement contains customary representations and warranties of
Barrett, including, among other things: (i) that the documents filed by Barrett
with the Commission since January 1, 1993 do not contain material misstatements
or omissions; (ii) that the information supplied to Barrett's petroleum
engineers was true and correct in all material respects and that no material
adverse change in the assets, properties, condition (financial or otherwise),
business or results of operations of Barrett ("Material Adverse Change") has
occurred in the matters covered by such engineers' report since September 30,
1994; (iii) that, except as previously disclosed to Plains, no wells of Barrett
have been overproduced such that they are likely to be shut-in or subject to
penalty, there have been no changes in proposed production allowables in such
wells, such wells have been drilled and (if completed) completed, operated and
produced in accordance with good industry practices, applicable laws and
applicable leases, there is no obligation or agreement to abandon any well that
is not or will not be abandoned and reclaimed in accordance with applicable
laws and good industry practices, proceeds from sales of hydrocarbons produced
are being received in a timely manner and are not being held in suspense by
third parties (other than up to $1,000,000) and no person has an option, call
or other similar right with respect to the oil and natural gas interests of
Barrett; (iv) that the information to be included herein and in the
Registration Statement in connection with the Merger will be free from material
misstatements and omissions; (v) that there has been no Material Adverse Change
with respect to Barrett, except as disclosed in its documents filed with the
Commission; (vi) as to actions taken or not taken that would jeopardize the
contemplated tax and accounting treatment of the Merger; (vii) as to title to
properties; (viii) as to employee benefit plans, employment agreements,
severance and "golden parachutes," and labor matters; (ix) with respect to
environmental matters; (x) with respect to pending or threatened litigation;
(xi) as to governmental licenses and permits, and compliance with laws; (xii)
that Barrett's financial advisor has rendered its written opinion that the
Exchange Ratio is fair to the stockholders of Barrett from a financial point of
view; and (xiii) as to the Barrett Board of Directors' actions with respect to
the Merger Agreement, the Merger, the Charter Amendment, the Stock Issuance and
related matters. In addition, the Merger Agreement contains representations and
warranties by Barrett as to its organization, capital structure, authority to
enter into the Merger Agreement and the binding effect of the Merger Agreement
on it.
 
  The Merger Agreement also contains similar customary representations and
warranties of Plains, as well as additional representations and warranties to
the effect that Rights Agreement has been amended so that it will not be
triggered by the Merger and that the Plains Board's approval of the Merger
Agreement and the Merger makes the "fair price" provisions of the Plains
Charter inapplicable to the Merger.
 
  In addition, the Merger Agreement contains customary representations and
warranties of Barrett and Sub, including, among other things, as to its
organization, capital structure, authority to enter into the Merger Agreement
and the binding effect of the Merger Agreement on it, and to the effect that it
was organized solely for the purpose of acquiring Plains and has not engaged in
any business since its formation which is not in connection with the Merger and
the Merger Agreement.
 
CONDUCT OF BUSINESS PENDING THE MERGER
 
  Pursuant to the Merger Agreement, each of Barrett and Plains has agreed that
during the period from the date of the Merger Agreement through the Effective
Time (except as otherwise specifically required by the terms of the Merger
Agreement), it will, and it will cause its respective subsidiaries to, in all
material respects, carry on their respective businesses in the ordinary course
and consistent with past practice and, to the extent consistent therewith and
with the terms of the Merger Agreement, use all reasonable efforts to preserve
intact their current business organizations, keep available the services of
their current officers and employees and preserve their relationships with
customers, suppliers and others having business dealings with them to the end
that their goodwill and ongoing businesses will be unimpaired at the Effective
Time.
 
  Without limiting the generality of the foregoing, each of Barrett and Plains
has agreed that, prior to the Effective Time, except as otherwise expressly
contemplated by the Merger Agreement, it will not, and will
 
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<PAGE>
 
not cause its respective subsidiaries to, without the prior written consent of
the other parties to the Merger Agreement: (i) (x) declare, set aside or pay
any dividends on, or make any other distributions in respect of, any of its
respective capital stock, or otherwise make any payments to its respective
stockholders in their capacity as such, other than (1) ordinary quarterly
dividends by Plains consistent with past practice in an amount not in excess of
$.06 per share, (2) dividends declared by Plains prior to the date of the
Merger Agreement, and (3) dividends payable to Plains or Barrett declared by
their respective subsidiaries, (y) split, combine or reclassify any of its
capital stock or issue or authorize the issuance of any other securities in
respect of, in lieu of or in substitution for shares of its capital stock, or
(z) purchase, redeem or otherwise acquire any shares of capital stock or other
securities, or any rights, warrants or options to acquire any such shares or
other securities, except in connection with the terms of their respective stock
option plans and certain other benefits plans of Plains; (ii) issue, deliver,
sell, pledge, dispose of or otherwise encumber any shares of its or its
subsidiaries' capital stock, any other voting securities or equity equivalent
or any securities convertible into, or any rights, warrants or options to
acquire, any such shares, voting securities or convertible securities or equity
equivalent (other than upon the exercise of stock options outstanding on the
date of the Merger Agreement in accordance with their current terms or in
accordance with the terms of certain benefits plans of Plains and Barrett);
(iii) amend its Certificate of Incorporation or amend in any material respects
its By-laws, other than the Charter Amendment and an amendment to Barrett's By-
laws to permit the election of the Plains Designees; (iv) acquire, merge or
consolidate with, or purchase a portion of the assets of or equity in, any
corporation, partnership, association or other business organization or
division thereof or otherwise acquire any assets, in each case that involves a
transaction exceeding $50,000 in the aggregate, or engage in any negotiations
with any person or entity concerning any such transaction, except that Plains
and Barrett may acquire oil and natural gas interests in the ordinary course of
business consistent with past practice; (v) except in the ordinary course of
business, sell, lease otherwise dispose of or agree to sell, lease or otherwise
dispose of, any business or line of business or any of its assets, in each case
that are material, individually or in the aggregate, to Plains and its
subsidiaries taken as a whole, or to Barrett and its subsidiaries taken as a
whole, respectively; (vi) make any capital expenditures, except in the ordinary
course of business; (vii) (A) pay, discharge, or satisfy any material claims,
liabilities, or obligations (absolute, accrued, asserted or unasserted,
contingent or otherwise), except for the payment, discharge or satisfaction of
its liabilities or its obligations in the ordinary course of business or in
accordance with their terms as in effect on the date of the Merger Agreement;
(B) adopt a plan of complete or partial liquidation or resolutions providing
for or authorizing such a liquidation or a dissolution, restructuring,
recapitalization or reorganization; (C) enter into any collective bargaining
agreement, successor collective bargaining agreement or amended collective
bargaining agreement; (D) change any accounting principle used by it, except
for such changes required to be implemented prior to the Effective Time
pursuant to generally accepted accounting principles or rules of the
Commission; or (E) settle or compromise any litigation brought against it,
other than settlements or compromises of any litigation where the amount paid
in settlement or compromise does not exceed $200,000, exclusive of amounts
covered by insurance; (viii) (A) enter into any new, or amend any existing,
severance agreement or arrangement, deferred compensation arrangement or
employment agreement with any officer, director or employee, except that,
subject to the Merger Agreement, Barrett and Plains may hire additional
employees to the extent deemed by their respective managements to be in the
best interests of Barrett or Plains, as the case may be, provided that neither
Plains nor Barrett may enter into any employment or severance agreement or any
deferred compensation arrangement with any such additional employees, (B) adopt
any new, or amend any existing, incentive, retirement or welfare benefit
arrangements, plans or programs for the benefit of current, former or retired
employees (other than amendment required by law or to maintain the tax
qualified status of such plans under the Code), or (C) grant any increases in
employee compensation, other than in the ordinary course or pursuant to
promotions, in each case consistent with past practice; (ix) except in the
ordinary course of business consistent with past practice, incur any
indebtedness for borrowed money or guarantee any such indebtedness or issue or
sell any debt securities or guarantee any debt securities of others or make any
loans, advances or capital contributions to, or investments in, any other
person, other than to Plains or any wholly owned subsidiary of Plains or to
Barrett or any wholly owned subsidiary of Barrett, respectively; or (x)
authorize or enter into any agreement to do any of the foregoing.
 
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  Pursuant to the Merger Agreement, during the period from the date of the
Merger Agreement through the Effective Time, Sub will not engage in any
activities of any nature except as expressly provided in or contemplated by the
Merger Agreement or incident thereto.
 
NO SOLICITATION
 
  Pursuant to the Merger Agreement, from the date of the Merger Agreement,
Plains will not, and will cause its subsidiaries and its officers, directors,
employees, agents and other representatives and those of any of its
subsidiaries not to, directly or indirectly, solicit or initiate any takeover
proposal or offer for Plains, and not to solicit or initiate, directly or
indirectly, discussions, negotiations, considerations or inquiries concerning a
takeover proposal or offer for Plains, from any person, or engage in
discussions or negotiations relating thereto, or provide to any other person
any information or data relating to Plains or its subsidiaries for the purpose
of, or have any substantive discussions with, any person relating to, or
otherwise cooperate with or assist or participate in, or facilitate, any
takeover proposal or offer or any inquiry or proposal which would reasonably be
expected to lead to any effort or attempt by any other person to seek to effect
a takeover proposal or offer, or agree to or endorse any such inquiry, takeover
proposal or offer; provided, however, that (i) Plains may engage in discussions
or negotiations with a third party who, without Plains taking any action which
is proscribed as provided in the Merger Agreement, seeks to initiate such
discussions or negotiations or may furnish such third party information
concerning Plains and its business, properties or assets (provided that such
third party executes a confidentiality agreement with Plains) and (ii) Plains'
Board of Directors may take and disclose to Plains' stockholders a position
contemplated by Rules 14d-9 and 14e-2(a) promulgated under the Exchange Act,
but in each case referred to in the foregoing clauses (i) and (ii) only to the
extent that a majority of the Board of Directors of Plains concludes in good
faith, after consultation with and based upon the written advice of Sidley &
Austin or Richards, Layton & Finger (which advice need not constitute an
opinion), Plains' counsel, that such action is necessary in order for the Board
of Directors of Plains not to breach its fiduciary obligations under applicable
law. Plains will promptly (but in no case later than 24 hours) notify Barrett
of any inquiry, takeover proposal or offer for Plains, including the material
terms and conditions thereof, but will not be required to indicate the identity
of the person or group making such takeover proposal or offer. Prior to
termination of the Merger Agreement, Plains has agreed that it will not enter
into any written agreement with any person that provides for, or in any way
facilitates, a takeover proposal or offer, other than a confidentiality
agreement. Except as permitted by the Merger Agreement, Plains has also agreed
to cease existing discussions, negotiations and other activities with any
parties (other than Barrett) relating to any possible takeover proposal or
offer. As used in the Merger Agreement, "takeover proposal" or "offer" means
any proposal or offer (other than a proposal or offer by Barrett or any of its
affiliates) for a tender or exchange offer, a merger, consolidation or other
business combination involving Plains or any subsidiary of Plains, or any
proposal to acquire in any manner a substantial equity interest in, or a
substantial portion of the assets of, Plains or any of its subsidiaries.
 
ACCESS TO INFORMATION
 
  The Merger Agreement provides that, subject to applicable provisions
regarding confidentiality, each of Barrett and Plains will, and will cause each
of its subsidiaries to, afford to the other parties, and to their accountants,
counsel, financial advisers and other representatives, reasonable access and
permit them to make such inspections as they may reasonably require during the
period from the date of the Merger Agreement through the Effective Time to all
their respective properties, books, contracts, commitments and records.
 
FEES AND EXPENSES
 
  Regardless of whether the Merger is consummated, except as described below
upon certain terminations of the Merger Agreement, all costs and expenses
incurred in connection with the Merger Agreement and the transactions
contemplated thereby will be paid by the party incurring such costs and
expenses.
 
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<PAGE>
 
  If Barrett terminates the Merger Agreement pursuant to clause (ii)(a) or (v)
under "--Termination" below, then Plains will pay to Barrett, within five
business days following such termination, an amount in cash equal to all out-
of-pocket expenses actually and reasonably incurred by Barrett and its
subsidiaries in connection with the Merger Agreement and the transactions
contemplated thereby. In addition, if within nine months after such
termination, Plains enters into an agreement with respect to a Third Party
Acquisition of Plains (a "Plains Acquisition Agreement") or there occurs, or
the Board of Directors recommends to the stockholders of Plains or resolves to
recommend to the stockholders, a Third Party Acquisition, then upon the
earliest of such events, Plains will immediately pay to Barrett an amount in
cash equal to $8,000,000 less the amount paid by Plains to Barrett pursuant to
the immediately preceding sentence in respect of Barrett's expenses. In
addition, if Barrett terminates the Merger Agreement pursuant to clause (ii)(b)
under "--Termination" below, or Plains terminates the Merger Agreement pursuant
to clause (iii)(b) under "--Termination" below, and, in addition, within nine
months after such termination Plains enters into a Plains Acquisition Agreement
or there occurs, or the Board of Directors recommends to the stockholders of
Plains or resolves to do so, a Third Party Acquisition, then, upon the earliest
of such events, Plains will immediately pay to Barrett cash in the amount of
$8,000,000. Also, if Barrett terminates the Merger Agreement pursuant to clause
(vi)(a) under "-- Termination" below, then Plains will immediately pay to
Barrett cash in the amount of $5,000,000 and, if within nine months thereafter,
Plains enters into a Plains Acquisition Agreement or there occurs, or the Board
of Directors recommends to the stockholders of Plains or resolves to recommend
to the stockholders, a Third Party Acquisition, then upon the earliest of such
events, Plains will immediately pay to Barrett cash in the amount of
$3,000,000. If Plains terminates the Merger Agreement pursuant to clause (viii)
under "--Termination" below or Barrett terminates the Merger Agreement pursuant
to clause (vi)(b) or (ix) under "--Termination" below, then Plains will
immediately pay to Barrett cash in the amount of $8,000,000. Notwithstanding
the foregoing, however, Plains will in no event be obligated to make payments
under the Merger Agreement exceeding, in the aggregate, $8,000,000 in
connection with any termination of the Merger Agreement.
 
  For purposes of the Merger Agreement, the term "Third Party Acquisition"
means the occurrence of any of the following events: (i) the acquisition of
Plains by merger, tender offer or otherwise, other than by Barrett or any of
its affiliates, (ii) except as contemplated by clause (iii) below, the
acquisition of more than 20% of the outstanding shares of Plains Common Stock
(measured after such issuance), or securities exercisable, convertible or
exchangeable into more than 20% of the outstanding shares of Plains Common
Stock (assuming the exercise, conversion or exchange of such securities), or
any other securities which represent, or are exercisable, convertible or
exchangeable into securities which represent, more than 20% of the voting power
of the outstanding securities of Plains (assuming the exercise, conversion or
exchange of such securities) ordinarily (absent the occurrence of any
contingency) having the right to vote in the election of directors of Plains,
by any person other than Barrett or its affiliates or (iii) the issuance to any
person (other than Barrett or its affiliates) of more than 30% of the
outstanding shares of Plains Common Stock (measured after such issuance), or
securities exercisable, convertible or exchangeable into more than 30% of the
outstanding shares of Plains Common Stock (assuming the exercise, conversion or
exchange of such securities), or any other securities which represent, or are
exercisable, convertible or exchangeable into securities which represent, more
than 30% of the voting power of the outstanding securities of Plains (assuming
the exercise, conversion or exchange of such securities) ordinarily (absent the
occurrence of any contingency) having the right to vote in the election of
directors of Plains, in connection with an acquisition by Plains of any other
person or entity.
 
PLAINS STOCK OPTIONS
 
  The Merger Agreement provides that, no later than the Effective Time, each
Plains Stock Option that is outstanding immediately prior to the Effective Time
pursuant to Plains' stock option plans will become and represent an option to
purchase the number of shares of Barrett Common Stock (decreased to the nearest
full share) determined by multiplying (i) the number of shares of Plains Common
Stock subject to such Plains Stock Option immediately prior to the Effective
Time by (ii) the Exchange Ratio, at an exercise price per
 
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<PAGE>
 
share of Barrett Common Stock (rounded down to the nearest whole cent) equal to
the exercise price per share of Plains Common Stock immediately prior to the
Effective Time divided by the Exchange Ratio. After the Effective Time, except
as provided in the Merger Agreement, each new Barrett stock option issued in
substitution for a Plains Stock Option will be exercisable upon the same terms
and conditions as were applicable under the related Plains Stock Option
simultaneously with the Effective Time.
 
REASONABLE EFFORTS
 
  Upon the terms and subject to the conditions set forth in the Merger
Agreement, each of the parties agrees to use all reasonable efforts to take, or
cause to be taken, all actions, and to do, or cause to be done, and to assist
and cooperate with the other parties in doing, all things necessary, proper or
advisable to consummate and make effective, in the most expeditious manner
practicable, the Merger and the other transactions contemplated by the Merger
Agreement and the prompt satisfaction of the conditions thereto, provided,
however, that neither of the parties is under any obligation to take any action
to the extent that the board of directors of such party shall conclude in good
faith, after consultation with, and based upon the written advice of,
respective counsel, that such action would cause a breach of that board of
directors' fiduciary obligations under applicable law.
 
REAL ESTATE TRANSFER AND GAINS TAX
 
  Pursuant to the Merger Agreement, Barrett and Plains agree that either Plains
or the Surviving Corporation will pay any real property transfer or gains tax
or similar tax, in each case attributable to the transfer of the beneficial
ownership of Plains' or its subsidiaries' real property, if any (collectively,
the "Gains Taxes"), and any penalties or interest with respect to the Gains
Taxes, payable in connection with the consummation of the Merger. Plains agrees
to cooperate with Sub in the filing of any returns with respect to the Gains
Taxes, including supplying in a timely manner a complete list of all real
property interests held by Plains or its subsidiaries and any information with
respect to such property that is reasonably necessary to complete such returns.
The portion of the consideration allocable to the real property of Plains and
its subsidiaries will be determined by Sub or Barrett in its reasonable
discretion. The stockholders of Plains will be deemed to have agreed to be
bound by the allocation established pursuant to the Merger Agreement in the
preparation of any return with respect to the Gains Taxes.
 
INDEMNIFICATION; DIRECTORS AND OFFICERS INSURANCE
 
  The Merger Agreement provides that from and after the Effective Time, Barrett
will indemnify and hold harmless all past and present officers and directors of
Plains and of its Subsidiaries to the full extent such persons may be
indemnified by Plains pursuant to the Plains Charter and the Plains By-laws for
acts or omissions occurring at or prior to the Effective Time and will advance
reasonable litigation expenses incurred by such officers and directors in
connection with defending any action arising out of such acts or omissions. In
addition, Barrett will provide, or cause the Surviving Corporation to provide,
for a period of not less than six years from the Effective Time, Plains'
current directors and officers with an insurance and indemnification policy
that provides coverage for events occurring through the Effective Time that is
no less favorable than the existing policy or, if substantially equivalent
insurance coverage is unavailable, the best available coverage; provided,
however, that Barrett and the Surviving Corporation will not be required to pay
an annual premium for such insurance in excess of two times the last annual
premium paid by Plains prior to the date of the Merger Agreement (which annual
premium Plains has represented and warranted to have been $90,274 in the
aggregate), but in such case will purchase as much coverage as possible for
such amount.
 
EMPLOYEE BENEFITS
 
  Pursuant to the Merger Agreement, at the Effective Time, all employee
benefits plans and programs will terminate, subject to all applicable laws, and
all vested rights and benefits of such benefit plans and programs will be
distributed to the eligible recipients in accordance with the terms of such
plans of Plains and its
 
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<PAGE>
 
subsidiaries, except that, with respect to the qualified benefit plans, the
parties may elect prior to the Effective Time to freeze benefit accruals in
lieu of terminating the plans as of the Effective Time. The officers and
employees of Plains and its subsidiaries will be provided by Barrett with
employee benefits under plans and programs which, in the aggregate, are no less
favorable than those provided pursuant to the plans and programs of Barrett and
its subsidiaries in effect on the date of the Merger Agreement. If Barrett or
any of its subsidiaries at any time provide benefits to retirees of Barrett or
any of its subsidiaries, retirees of Plains and its subsidiaries will be
provided benefits which, in the aggregate, are no less favorable than those
provided to retirees of Barrett and its subsidiaries.
 
STAY BONUSES; MERIT BONUSES; SEVERANCE POLICY
 
  The Merger Agreement provides that, after consultation with Barrett, Plains
will be permitted to offer and pay bonuses, in addition to any bonuses or
payments pursuant to any existing bonus or incentive plans of Plains, in an
aggregate amount up to $625,000, payable to (i) non-officer employees who
remain in the employ of Plains or its subsidiaries until a date set by Plains,
which date will be no earlier than the date three months after the Effective
Time or (ii) non-officer employees whose performance and dedication to Plains
or its subsidiaries merits, in the discretion of the Chief Executive Officer of
Plains, special compensation. In addition, Barrett is permitted, after
consultation with Plains, to make similar payments in the aggregate amount of
$625,000 to its non-officer employees.
 
  The Merger Agreement further provides that, with respect to officers and
employees who are or will be terminated, Barrett will maintain Plains'
severance policy as in effect on the date of the Merger Agreement, or will
replace such policy with a policy providing equal or more favorable
compensation, for a period of at least two years from the Effective Time.
 
  Barrett also has agreed to honor or cause to be honored all severance and
employment agreements that existed as of February 15, 1995 with Plains'
officers and employees.
 
  Barrett has agreed that, to the extent not inconsistent with any applicable
law or regulation, for one year after the Effective Time, before filling any
job vacancy or newly created position, Barrett and its subsidiaries will
undertake reasonable efforts to send written notification of such vacancy or
position to any officers or employees of Plains and its subsidiaries who were
terminated subsequent to the Effective Time by Plains, Barrett or a subsidiary
of either of them and who had been employed in a comparable position (as
determined by Barrett in its reasonable discretion) at the Effective Time.
 
  In addition to the matters set forth above, if any former employee of Plains
or its subsidiaries is hired by Barrett or its subsidiaries in accordance with
the Merger Agreement within one year after the Effective Time, the years of
service of such employee with Plains, its subsidiaries and any prior employer
will be credited for purposes of eligibility and vesting of benefits and, in
the case of employment opportunities requiring a relocation of the employee's
place of residence, such employee will be provided relocation expenses and
reimbursement under Barrett's reimbursement policy for transferred or newly
hired employees in effect on the date of the Merger Agreement.
 
  Barrett also has agreed to arrange for professional outplacement services for
officers and employees of Plains and its subsidiaries who are terminated as a
result of, or within 18 months following, the Merger, at a cost to Barrett not
in excess of $100,000 in the aggregate.
 
CONDITIONS TO THE MERGER
 
  The Merger Agreement provides that the respective obligations of each party
to effect the Merger is subject to the fulfillment or waiver (where
permissible) at or prior to the Effective Time of each of the following
conditions: (i) the Merger shall have been approved by the requisite vote of
the holders of Plains Common Stock, and the Charter Amendment and Stock
Issuance shall have been approved by the requisite
 
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<PAGE>
 
vote of the holders of Barrett Common Stock; (ii) the Barrett Common Stock
issuable in the Merger and pursuant to Plains Stock Options shall have been
authorized for listing on the NYSE, upon official notice of issuance; (iii) the
applicable waiting period under the HSR Act shall have expired or been
terminated; (iv) the Registration Statement shall have become effective in
accordance with the provisions of the Securities Act and all necessary state
securities or "Blue Sky" authorizations shall have been received; (v) no
governmental entity or court of competent jurisdiction shall have enacted,
issued, promulgated, enforced or entered any law, rule, regulation, executive
order, decree, injunction or other order (whether temporary, preliminary or
permanent) which is then in effect and has the effect of prohibiting the Merger
or the transactions contemplated thereby; provided that, in the case of any
such decree, injunction or other order, each of the parties shall have used
reasonable best efforts to prevent the entry of any such injunction or other
order and to appeal as promptly as practicable any decree, injunction or other
order that may be entered; and (vi) all authorizations, consents, orders,
declarations or approvals of, or filings with, or terminations or expirations
of waiting periods imposed by, any governmental entity, the failure to obtain
which would have a material adverse effect on Barrett (assuming the Merger had
taken place) shall have been obtained, shall have occurred or shall have been
filed.
 
  The Merger Agreement also provides that the obligation of Plains to effect
the Merger is subject to the fulfillment or waiver at or prior to the Effective
Time of the following additional conditions: (i) Barrett and Sub shall have
performed in all material respects each of their agreements contained in the
Merger Agreement required to be performed on or prior to the Effective Time and
each of the representations and warranties of Barrett and Sub contained in the
Merger Agreement shall be true and correct in all material respects on and as
of the Effective Time as if made on and as of such date; (ii) receipt by Plains
of customary officers' certificates and opinions of counsel to Barrett; and
(iii) Barrett's Board of Directors shall have been increased by four and the
vacancies thereby created shall be filled at the Effective Time by the Plains
Designees.
 
  The Merger Agreement further provides that the obligations of Barrett and Sub
to effect the Merger are subject to the fulfillment or waiver at or prior to
the Effective Time of the following additional conditions: (i) Plains shall
have performed in all material respects each of its agreements contained in the
Merger Agreement required to be performed on or prior to the Effective Time and
each of the representations and warranties of Plains contained in the Merger
Agreement shall be true and correct in all material respects on and as of the
Effective Time as if made on and as of such date; (ii) receipt by Barrett of
customary officers' certificates and opinions of counsel to Plains; (iii)
receipt by Barrett of required third party consents and approvals; and (iv)
based on the advice of Arthur Andersen LP and such other advice as Barrett may
deem relevant, Barrett shall have no reasonable basis for believing that the
Merger will not be able to be accounted for as apooling of interests.
 
TERMINATION
 
  The Merger Agreement may be terminated at any time prior to the Effective
Time, whether before or after any approval by the stockholders of Plains: (i)
by mutual written consent of Barrett and Plains; (ii) by Barrett if (a) Plains
shall have failed to comply in any material respect with any of its covenants
or agreements contained in the Merger Agreement required to be complied with by
Plains prior to the date of such termination, which failure to comply has not
been cured within five business days following receipt by Plains of notice of
such failure to comply, (b) the stockholders of Plains shall have failed to
approve the Merger at the Plains Special Meeting, or (c) the stockholders of
Barrett shall have failed to approve the Charter Amendment or the Stock
Issuance at the Barrett Special Meeting; (iii) by Plains if (a) Barrett or Sub
shall have failed to comply in any material respect with any of its covenants
or agreements contained in the Merger Agreement required to be complied with by
Barrett or Sub prior to the date of such termination, which failure to comply
has not been cured within five business days following receipt by Barrett of
notice of such failure to comply, (b) the stockholders of Plains shall have
failed to approve the Merger at the Plains Special Meeting, or (c) the
stockholders of Barrett shall have failed to approve the Charter Amendment or
the Stock Issuance at the Barrett Special Meeting; (iv) by either Barrett or
Plains if (a) the Merger has not been effected on or
 
                                       95
<PAGE>
 
prior to the close of business on December 31, 1995; provided, however, that
the right to terminate the Merger Agreement pursuant to this clause shall not
be available to any party whose failure to fulfill any obligation of the Merger
Agreement has been the cause of, or resulted in, the failure of the Merger to
have occurred on or prior to the aforesaid date, or (b) any court of competent
jurisdiction or any governmental, administrative or regulatory authority,
agency or body shall have issued an order, decree or ruling or taken any other
action permanently enjoining, restraining or otherwise prohibiting the
transactions contemplated by the Merger Agreement and such order, decree,
ruling or other action shall have become final and nonappealable; (v) by either
Barrett or Plains if there has been (a) a material breach by the other of any
representation or warranty that is not qualified as to materiality or (b) a
breach by the other of any representation or warranty that is qualified as to
materiality, in each case which breach has not been cured within five business
days following receipt by the breaching party of notice of the breach; (vi) by
Barrett, (a) if the Board of Directors of Plains shall not have recommended, or
shall have resolved not to recommend, or shall have modified or withdrawn its
recommendation of the Merger or declaration that the Merger is fair to and
advisable and in the best interests of Plains and its stockholders, or shall
have resolved to do so, or (b) if the Board of Directors of Plains shall have
recommended, or shall have resolved to recommend, to the stockholders of Plains
any takeover proposal or offer for Plains; (vii) by Plains if the Board of
Directors of Barrett shall not have recommended, or shall have resolved not to
recommend, or shall have modified or withdrawn its recommendation of the Merger
Agreement, the Charter Amendment and the Stock Issuance or declaration that
such transactions are fair to and advisable and in the best interest of Barrett
and its stockholders, or shall have resolved to do so; (viii) by Plains if
there is an offer to acquire all of the outstanding shares of Plains Common
Stock or substantially all of the assets of Plains for consideration that
provides stockholders of Plains a value per share of Plains Common Stock which,
in the good faith judgment of the Board of Directors of Plains, that is higher
than the consideration per share pursuant to the Merger; or (ix) by Barrett, if
a Third Party Acquisition occurs.
 
  In the event of termination of the Merger Agreement by either Barrett or
Plains, the Merger Agreement shall forthwith become void and there shall be no
liability hereunder on the part of Plains, Barrett or Sub or their respective
officers or directors, except as provided in the Merger Agreement.
 
AMENDMENT
 
  The Merger Agreement may be amended by the parties thereto, by or pursuant to
action taken by their respective Boards of Directors, at any time before or
after approval of the Merger by the stockholders of Plains but, after any such
approval by stockholders of Plains, no amendment will be made which changes the
Exchange Ratio or which in any way materially adversely affects the rights of
such stockholders, without the further approval of such stockholders.
 
WAIVER
 
  The Merger Agreement provides that, at any time prior to the Effective Time,
the parties thereto may (i) extend the time for the performance of any of the
obligations or other acts of the other parties thereto, (ii) waive any
inaccuracies in the representations and warranties contained herein or in any
document delivered pursuant thereto and (iii) waive compliance with any of the
agreements or conditions contained herein which may legally be waived.
 
                               CERTAIN LITIGATION
 
  On October 20, 1994, Plains issued a press release stating that it had
authorized its financial advisors to help Plains study strategic alternatives
in light of a recent Schedule 13D filing by Cross Timbers. The press release
stated that as part of the study, the financial advisors would seek indications
of interest from certain possible merger partners. The press release also
indicated that the Plains Board had amended its Rights Agreement.
 
 
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<PAGE>
 
  On November 2, 1994, a putative class action was filed in Delaware Chancery
Court. In that case, entitled Miller v. Cody, et al., the plaintiff has alleged
that certain named directors and Plains have, among other things, breached
their fiduciary duties by unreasonably amending the Rights Agreement and
otherwise acting to entrench themselves in office. Plaintiff seeks various
forms of injunctive relief, damages and an award of plaintiff's costs and
disbursements. Plains and the named directors deny the allegations of
wrongdoing in the complaint and intend to pursue a vigorous defense. A putative
class action entitled Behrens v. Miller, et al., that was filed on October 21,
1994, was voluntarily dismissed without prejudice by the plaintiff. The
allegations and relief sought in the Behrens case were similar to those in the
Miller action described above.
 
  On May 3, 1995, Plains announced it had executed the Merger Agreement with
Barrett. Also on May 3, 1995, a putative class action, entitled Crandon Capital
Partners v. James A. Miller, et al., was filed in Delaware Chancery Court
against Plains and the members of its Board of Directors. In this suit it is
alleged that, among other things, the consideration to be paid Plains'
stockholders pursuant to the Merger Agreement is inadequate and "substantially
below the fair or inherent value of Plains." Plaintiff seeks various forms of
declaratory and injunctive relief, damages and an award of plaintiff's costs
and disbursements. Plains and the directors deny the allegations of wrongdoing
in the complaint and intend to pursue a vigorous defense.
 
                                    EXPERTS
 
  The consolidated financial statements of Barrett as of September 30, 1993 and
1994 and for each of the three years in the period ended September 30, 1994,
incorporated by reference to Barrett's Annual Report on Form 10-K for the
fiscal year ended September 30, 1994, have been audited by Arthur Andersen LLP,
independent auditors, as set forth in their report thereon included therein and
incorporated herein by reference. Such consolidated financial statements are
incorporated herein by reference in reliance upon such report given upon the
authority of such firm as experts in accounting and auditing.
 
  The consolidated financial statements of Plains as of December 31, 1993 and
1994 and for each of the three years in the period ended December 31, 1994,
incorporated by reference to Plains' Annual Report on Form 10-K for the year
ended December 31, 1994, have been audited by Arthur Andersen LLP, independent
auditors, as set forth in their report thereon included therein and
incorporated herein by reference. Such consolidated financial statements are
incorporated herein by reference in reliance upon such report given upon the
authority of such firm as experts in accounting and auditing.
 
  Representatives of Arthur Andersen LLP are expected to be present at the
Special Meetings, where they will have the opportunity to make a statement if
they desire to do so and will be available to respond to appropriate questions.
 
                                 LEGAL OPINIONS
 
  The legality of the Barrett Common Stock being offered hereby is being passed
upon for Barrett by Simpson Thacher & Bartlett (a partnership which includes
professional corporations), special counsel to Barrett, and by Bearman
Talesnick & Clowdus Professional Corporation. Attorneys employed by Bearman
Talesnick & Clowdus Professional Corporation beneficially own approximately
22,000 shares of Barrett Common Stock.
 
  Simpson Thacher & Bartlett (a partnership which includes professional
corporations), special counsel to Barrett, and Sidley & Austin, counsel to
Plains, have delivered opinions concerning certain federal income tax
consequences of the Merger. See "THE MERGER--Certain Federal Income Tax
Consequences."
 
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<PAGE>
 
                  OTHER INFORMATION AND STOCKHOLDER PROPOSALS
 
  Barrett management and Plains management know of no other matters that may
properly be, or which are likely to be, brought before the Barrett Special
Meeting or the Plains Special Meeting, respectively. However, if any other
matters are properly brought before such Special Meetings, the persons named in
the enclosed proxy or their substitutes will vote the proxies in accordance
with the recommendations of management.
 
  In order to be considered for inclusion in the proxy statement for the 1995
annual meeting, if any, of stockholders of Plains, any stockholder proposal
intended to be presented at the meeting must have been received by Plains on or
before August 15, 1995.
 
  In order to be considered for inclusion in the proxy statement for the next
annual meeting of stockholders of Barrett, any stockholder proposal intended to
be presented at the meeting must have been received by Barrett on or before
September 14, 1995.
 
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<PAGE>
 
           BARRETT MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                      CONDITION AND RESULTS OF OPERATIONS
 
LIQUIDITY AND CAPITAL RESOURCES
 
  As of March 31, 1995, Barrett's total assets were $131.8 million compared to
$105.9 million as of September 30, 1994. This represents an increase of $25.9
million or 24.5%. Property and equipment increased $21.4 million (27.9%) and
current assets increased $4.5 million (15.5%). Working capital increased by
$10.8 million to $6.6 million. These increases are primarily the result of
increased investment in oil and gas properties, increased gas production that
began in the first quarter of fiscal 1995 and borrowings under Barrett's line
of credit.
 
  During the six month period ended March 31, 1995, Barrett borrowed $31
million on its line of credit with a bank. The line of credit provides up to
$80 million with a borrowing base of $40 million. Barrett has voluntarily
requested that the maximum borrowing be limited to $35 million.
 
  For the respective six months ended March 31, 1995 and 1994, operations
provided $5.9 million and $6.4 million of cash flow before working capital
changes. The decrease is primarily due to lower gas prices which resulted in
decreased net income.
 
  Barrett invested $34.4 million in the acquisition of property and equipment
during the six months ended March 31, 1995 compared to $14.8 million for the
same period of fiscal 1994. During this period, Barrett continued its
exploration and development activities in the Piceance Basin of Colorado, the
Wind River Basin in Wyoming and the Arkoma and Anadarko Basins of Oklahoma.
 
  During December 1994, Barrett began production of its Cave Gulch discovery in
the Wind River Basin and began operation of its gas plant and gathering system
extension in the Piceance Basin. These actions significantly increased
production to Barrett's interest.
 
  On May 3, 1995, Barrett announced the proposed Merger, which is anticipated
to be accounted for using the pooling of interests method of accounting. See
"THE MERGER--Anticipated Accounting Treatment." As of December 31, 1994, Plains
Petroleum reported proved reserves of 11 million barrels of oil and 312.5 Bcf
of natural gas.
 
  Due to low natural gas prices, Barrett continues to evaluate its
opportunities for investing in oil and natural gas properties. Management
believes that as a result of this evaluation, its oil and natural gas investing
activities for the remainder of the year may be reduced compared to previous
plans for the year.
 
  Management believes that its current cash position, anticipated cash flow and
borrowing capacities will adequately fund its fiscal 1995 anticipated
exploration and development activities.
 
RESULTS OF OPERATIONS
 
 THREE AND SIX MONTHS ENDED MARCH 31, 1995 VS. THREE AND SIX MONTHS ENDED MARCH
31, 1994
 
  Net income for the quarters ended March 31, 1995 and 1994 was $.9 million
($.07 per share) and $1.7 million ($.14 per share), respectively. The decrease
was due primarily to a reduction of average gas prices, which were 29% lower
for the fiscal 1995 quarter than the fiscal 1994 quarter, and the resulting
effect on oil and gas production revenue. Other factors contributing to the
decrease in net income included increases in general and administrative
expenses and interest expense.
 
  For the six months ended March 31, 1995 and 1994, net income was $1.1 million
($0.9 per share) and $2.8 million ($.23 per share), respectively. Due primarily
to lower gas prices, production revenue net of lease
 
                                       99
<PAGE>
 
operating expense and depreciation, depletion and amortization decreased from
$4.2 million to $3.1 million during this period. Increases in gas gathering
revenue due to the gathering system extension in the Piceance Basin were offset
by increases in general and administrative expenses and interest expenses.
 
  Production revenue increased from $4.9 million in the 1994 fiscal quarter to
$6.3 million in the 1995 fiscal quarter. During the 1995 fiscal quarter,
Barrett sold 25,000 barrels of oil and 4,246,000 Mcf of natural gas at an
average price of $1.41 per Mcf of natural gas and $14.26 per barrel of oil.
During the comparable quarter of fiscal 1994, Barrett sold 16,000 barrels of
oil and 2,325,000 Mcf of natural gas at an average price of $2.04 per Mcf of
natural gas and $12.29 per barrel of oil. In the 1995 fiscal quarter, as
compared to the 1994 fiscal quarter, production quantities increased 82% on a
barrel of oil equivalent basis, while product prices decreased 29%. Daily sales
on an Mcfe basis were 49,000 and 26,900 for the respective quarters ended March
31, 1995 and 1994.
 
  For the six months ended March 31, 1995, production revenue was $10.3 million
compared to revenues of $9.4 million for the six months ended March 31, 1994.
The significant increases in production were the result of the operation of the
gas plant and gas gathering system extension in the Piceance Basin and the
production from the Cave Gulch project in the Wind River Basin, both of which
commenced in December 1994.
 
  Total revenues were $14.5 and $9.6 million for the quarters ended March 31,
1995 and 1994 and total expenses in such quarters were $13.6 million and $7.9
million, respectively. For the six month periods, total revenues were $29.6
million and $19.5 million, respectively, and expenses were $28.4 million and
$16.6 million, respectively. The largest portion of the increases in revenues
and expenses for the quarter and the six months was attributable to trading
activities.
 
  In 1995, trading revenues were $7.8 million for the second quarter ($4.3
million in 1994) and $18.5 million for the six month period ($9.4 million in
1994). The associated costs of trading were $7.5 million and $4.2 million for
the quarter ended March 31, 1995 and 1994, respectively, and $17.9 million and
$9.0 million for the respective six month periods. Gross profit from trading
increased to $0.3 million in the 1995 quarter from $0.2 million for the 1994
quarter and to $0.7 million from $0.4 million for the 1995 and 1994 six month
periods, respectively.
 
  General and administrative expenses for the quarter ended March 31, 1995
increased to $1.5 million from $1.2 million in the comparable 1994 quarter. For
the six month periods, these expenses increased from $2.4 million to $3.1
million. These increases were primarily due to expenses related to Barrett's
expansion of its oil and natural gas activities in both existing and new
prospect areas.
 
  Depreciation, depletion and amortization increased from $1.8 million to $3.0
million for the quarter and from $3.5 million to $4.8 million for the six month
period. The increase was due to production volume increases. During fiscal 1995
and 1994, depletion on oil and natural gas production was recorded at $3.90 and
$4.26 per barrel of oil equivalent, respectively.
 
  Barrett's largest source of operating income is from sales of its natural gas
and oil production. Therefore, the levels of Barrett's revenues and earnings
are affected by prices at which natural gas and oil are being sold. This is
particularly true with respect to natural gas, which accounted for
approximately 94% of Barrett's fiscal 1995 production revenues through March
31, 1995. As a result, Barrett's operating results for any prior period are not
necessarily indicative of future operating results because of the fluctuations
in natural gas and oil prices and the lack of predictability of those
fluctuations, as well as changes in production levels.
 
 
                                      100
<PAGE>
 
 FISCAL 1994 VS. FISCAL 1993
 
  During fiscal 1994, Barrett earned net income of $4.4 million ($.37 per
share) compared to net income of $5.8 million ($.53 per share) in fiscal 1993.
The fiscal 1994 results included a tax benefit of $1.5 million due to an
increase in the financial reporting value of Barrett's net operating loss
carryover. Without the tax benefit from the net operating loss carryover,
Barrett's net income after taxes would have been $2.9 million ($.24 per share).
The 1993 fiscal results included a tax benefit of $2.2 million from the value
of the net operating loss carryover.
 
  Revenues decreased 3% from fiscal 1993 to $41.3 million in fiscal 1994 and
operating expenses were virtually unchanged at $36.7 million. In fiscal 1994,
production revenue increased $2.6 million and trading revenues decreased $3.9
million. In fiscal 1994, lease operating expenses increased $0.8 million,
depreciation, depletion and amortization increased $0.8 million, and the cost
of trading decreased $3.8 million.
 
  Production revenues increased $2.6 million in fiscal 1994, primarily due to a
26% increase in gas production to 9.1 Bcf. Offsetting the gas production
increase were a 28% decrease in oil production, a 2% decrease in the average
natural gas sales price and an 18% decrease in the average oil sales price.
During fiscal 1994, Barrett produced 24,800 Mcf of natural gas per day and 148
barrels of oil per day. Natural gas production accounted for 97% of total
production on an energy equivalent basis. The Arkoma and Piceance Basin
properties accounted for 45% and 44%, respectively, of total production. During
fiscal 1994, the average natural gas sales price was $1.85 per Mcf ($1.89 in
fiscal 1993) and the oil sales price was $14.34 per barrel ($17.59 in fiscal
1993). The decreased sales prices were due to an overall deterioration in the
commodities markets of both natural gas and oil, especially in the natural gas
market during the last half of Barrett's 1994 fiscal year. During fiscal 1994,
the Arkoma production was sold for an average of $1.89 per Mcf and the Piceance
production was sold for an average of $1.79 per Mcf.
 
  Lease operating expenses of $3.5 million averaged $.38 per Mcfe ($2.26 per
barrel of oil equivalent) of production in fiscal 1994 compared with $.36 per
Mcfe ($2.13 per barrel of oil equivalent) in fiscal 1993. Depreciation,
depletion and amortization increased $0.8 million in fiscal 1994, primarily due
to production increases. During fiscal 1994, depreciation, depletion and
amortization on natural gas and oil production was provided at an average rate
of $.69 per Mcfe ($4.19 per barrel of oil equivalent) compared to an average
rate of $.75 per Mcfe ($4.49 per barrel of oil equivalent) in fiscal 1993.
 
  The gross margin on trading activities decreased to $0.9 million in fiscal
1994 from $1.0 million in fiscal 1993. Natural gas trading volumes decreased 2%
to 13.1 Bcf in fiscal 1994.
 
  During fiscal 1994, Barrett hedged 6.8 Bcf (52%) of its natural gas trading
volumes at a net cost of $713,000 and 920,000 Mcf (10%) of its natural gas
production at a net cost of $65,000. Barrett entered into the hedging
arrangements to reduce its exposure to price risks associated with commodities
markets for natural gas. The hedging results for trading activities eliminated
price fluctuations of natural gas purchases so that Barrett realized the gross
profit margins anticipated upon entering into the trading arrangements.
Although hedging transactions reduce Barrett's exposure to losses as a result
of unfavorable price changes, the transactions also limit Barrett's ability to
benefit from favorable price changes. With respect to trading activities,
Barrett will not generally enter into a commitment for either a purchase or a
sale unless either (i) it has established a commitment for an offsetting sale
or purchase or (ii) it has established a hedge arrangement with a counter party
that creates a similar matching position.
 
  General and administrative expenses of $4.7 million in fiscal 1994 were 84%
greater than in fiscal 1993. The fiscal 1994 amount was net of $2.4 million of
operating fee recoveries compared to a $2.9 million recovery in fiscal 1993.
The increased general and administrative expense was due to additional costs
incurred by Barrett to expand its activities and to explore in other areas.
 
  During fiscal 1994, Barrett recorded a $67,000 net income tax expense
compared to a $154,000 net income tax expense in fiscal 1993. The fiscal 1994
expense consisted of $1.6 million of income tax expense on current income
offset by a $1.5 million reduction in the valuation allowance for deferred
income taxes. The
 
                                      101
<PAGE>
 
valuation allowance was reduced to reflect the effect of expected future
taxable income from increased oil and natural gas reserves.
 
  Barrett's results of operations depend primarily on the production of natural
gas which accounted for 98% of Barrett's reserves and 97% of its production in
fiscal 1994. Therefore, a significant portion of Barrett's future results will
depend on both the volume of natural gas production and the sales price for
gas. Barrett continues to explore for natural gas and oil to increase its
production and it uses various selling arrangements and risk management
techniques to minimize price risks. However, the lack of predictability of both
production volumes and sales prices may influence future operating results.
 
 FISCAL 1993 VS. FISCAL 1992
 
  During fiscal 1993, Barrett earned net income of $5.8 million ($.53 per
share) compared to net income of $1.5 million ($.15 per share) in fiscal 1992.
The fiscal 1993 results include a tax benefit of $2.2 million due to an
increase in the financial reporting value of Barrett's net operating loss
carryover. Without the tax benefit from the net operating loss carryover,
Barrett's net income after taxes would have been $3.6 million ($.33 per share)
in fiscal 1993. The fiscal 1992 results included a tax benefit of $332,000 from
the value of the net operating loss carryover and $583,000 for the cumulative
effect of adopting Statement of Financial Accounting Standards No. 109 to
account for income taxes effective October 1, 1991. Net income before income
taxes and the cumulative effect of change in accounting method was $5.9 million
in fiscal 1993 compared to $0.9 million in fiscal 1992.
 
  Revenues increased 76% from its fiscal 1992 level to $42.7 million in fiscal
1993 and operating expenses increased 58% to $36.8 million in fiscal 1993. In
fiscal 1993, production revenue increased $8.4 million and trading revenues
increased $9.6 million. These increases were offset by increases of $1.3
million in lease operating expenses, $2.9 million in depreciation, depletion
and amortization and $8.7 million in the cost of trading.
 
  In fiscal 1993, production revenues increased $8.4 million due to a 106%
increase in natural gas production and a 36% increase in oil production, along
with a 19% increase in the average natural gas sales price but offset by an 8%
decline in the average oil sales price. During fiscal 1993, Barrett produced
19,800 Mcf of natural gas per day and 205 barrels of oil per day. Natural gas
production accounted for 94% of total production on an energy equivalent basis
of 1.3 million barrels of oil equivalent (7.7 Bcfe). On an energy equivalent
basis, the Arkoma and Piceance Basin properties accounted for 48% and 32%,
respectively, of total production. During fiscal 1993, the average natural gas
sales price was $1.89 per Mcf ($1.59 in fiscal 1992) and the average oil sales
price was $17.59 per barrel ($19.09 in fiscal 1992). The increased natural gas
sales price was due to an overall improvement in natural gas markets and
increased production in the Arkoma Basin which is sold for a higher sales price
than natural gas sold from Barrett's other properties. During fiscal 1993, the
Arkoma production was sold for $1.90 per Mcf and the Piceance production was
sold for $1.82 per Mcf. In fiscal 1993, oil prices decreased due to a general
decline in the market price for oil production.
 
  Lease operating expenses of $2.7 million averaged $.36 per Mcfe ($2.13 per
barrel of oil equivalent) of production in fiscal 1993 compared with $.36 per
Mcfe ($2.16 per barrel of oil equivalent) in fiscal 1992. Depreciation,
depletion and amortization increased $2.9 million primarily due to production
increases in fiscal 1993. During fiscal 1993, depreciation, depletion and
amortization on oil and natural gas production was provided at an average rate
of $.75 per Mcfe ($4.49 per barrel of oil equivalent) compared to an average
rate of $.76 per Mcfe ($4.56 per barrel of oil equivalent) in fiscal 1992.
 
  As of July 1, 1993, Barrett sold all of its properties located in the
Wattenberg field in northeast Colorado. The Wattenberg properties accounted for
7% of natural gas production and 43% of oil production during the first nine
months of fiscal 1993. During fiscal 1993, Barrett collected fees of $1.0
million for operating approximately 122 wells in the Wattenberg field.
 
  The gross margin on trading activities increased to $1.0 million in 1993 from
$125,000 in fiscal 1992. The fiscal 1992 results were net of a $268,000
allowance for future losses on trading activities. Natural gas
 
                                      102
<PAGE>
 
trading volumes increased 26% to 13.4 Bcf in fiscal 1993. The improved results
were due to increased volumes and implementation of a hedging strategy to
minimize the price risks associated with trading activities.
 
  During fiscal 1993, Barrett hedged 5.9 Bcf (44%) of its natural gas trading
volumes for a gain of $1.2 million and 1.5 Bcf (21%) of its natural gas
production at a cost of $437,000. In addition, Barrett recorded a gain of
$762,000 from the mutual cancellation of a natural gas trading contract and the
related price hedge.
 
  General and administrative expenses of $2.6 million in 1993 were 24% greater
than in fiscal 1992. The fiscal 1993 amount was net of $2.9 million of
operating fee recoveries compared to a $2.6 million recovery in 1992. The
increased general and administrative expense was due to additional costs
incurred by Barrett to expand its activities and to explore in other areas.
 
  Other income of $584,000 in fiscal 1993 includes $423,000 related to the
favorable resolution of a disputed oil and gas operators claim. Barrett had
previously recorded a liability for the claim.
 
  During fiscal 1993, Barrett recorded a $154,000 net income tax expense
compared to an $18,000 net income tax expense in 1992. The fiscal 1993 expense
consisted of $2.4 million of income tax expense on current income offset by a
$2.2 million reduction in the valuation allowance for deferred income taxes.
The valuation allowance was reduced to reflect increased natural gas and oil
reserves that were expected to generate future taxable income and the tax gain
realized on the sale of the Wattenberg properties.
 
                                      103
<PAGE>
 
 PLAINS MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
                                 OF OPERATIONS
 
GENERAL
 
  In 1994, Plains achieved growth in oil and natural gas reserves of 11%
through a combined program of acquisitions, exploration and exploitation. In a
highly competitive market for a limited quantity of quality properties, Plains
successfully acquired 20 Bcf of natural gas and 2.5 million barrels of oil.
Exploration and exploitation achievements added another 19.6 Bcf of natural gas
and 2.3 million barrels of oil in 1994. In a year marked by fluctuating and
declining prices resulting in production curtailments, Plains reported net
earnings of $.68 per share in 1994 as compared to $.18 per share in 1993.
Concentrated efforts to reduce operating costs and improve operating
efficiencies offset declines in revenues stemming from lower prices.
 
  In the first quarter of 1995, record oil production, in addition to a 36%
higher average oil price, resulted in significantly (85%) increased oil
revenues as compared to the first quarter of 1994. Natural gas revenues were
below the 1994 first quarter due to lower natural gas prices realized for
increased natural gas volumes sold. In the 1995 first quarter, exploration
expense was substantially above the 1994 first quarter principally due to an
unsuccessful exploratory Louisiana well. In addition to the higher exploration
costs and increased production costs associated with an increase in the number
of wells owned by Plains, other expenses which increased, including interest
expense on higher debt balances and increased depletion charges related to
property additions, offset the higher revenues and resulted in lower earnings
for the 1995 first quarter as compared to the 1994 first quarter.
 
LIQUIDITY AND CAPITAL RESOURCES
 
  As of March 31, 1995, Plains' working capital was $1.9 million, with a ratio
of current assets to current liabilities of 1.25 to 1. Cash provided by
operating activities during the first quarter of 1995 was used to fund drilling
programs, reduce debt, pay dividends and acquire properties.
 
  Plains' 1995 planned capital spending, excluding acquisitions, is
approximately $38 million, up approximately $16 million from the 1994 level.
Approximately two-thirds of Plains' first quarter capital spending of $5
million focused on the exploitation of Plains' existing properties and
production enhancement projects. The balance was utilized in exploration
drilling and the development of new prospects. During the first quarter, the
first of two deep Louisiana exploratory prospects was unsuccessful at a net
cost of approximately $600,000. In the second quarter, the drilling contractor,
operating under a turnkey contract, elected to plug and abandon the second deep
well due to unresolved drilling problems with a net cost to Plains of
approximately $150,000. Drilling of an exploratory well located in the Gulf of
Mexico on Ship Shoal Blocks 275/292 commenced in May 1995. Plains has a one-
third working interest in this project at an estimated net drilling cost of
$884,000.
 
  In the first quarter of 1995, Plains' secondary recovery program concentrated
on the Cambridge Unit located in Wyoming and on the Moss and Foster Grayburg
San Andres Units located in Texas. Development projects are concentrated in
Wyoming, New Mexico and Texas. In Wyoming, a well in the Meeteetse field
producing from the Frontier Muddy formation was placed on production. Two
additional wells are planned for 1995. In the Teague Field located in New
Mexico, Plains has three Simpson-McKee producing wells, a fourth well being
drilled and a fifth well in the permitting stage. An enhanced recovery project
for the field is currently being evaluated. Two offset wells in the Sean Andrew
Field in Texas, a 1994 discovery, were placed on production. Another well is
being completed and a fourth well is being drilled. Other Texas projects
include a well in the Deckers Prairie Field in Montgomery County and the
completion of the Halls Bayou Ranch No. 2 well in Galveston County which was
placed on production.
 
  In Kansas, a new 2,200 horsepower field compressor station has been placed in
operation on the Hugoton Field gathering system and is anticipated to enhance
the Company's ability to increase its rate of production from the Field.
 
 
                                      104
<PAGE>
 
  To date the drilling programs have been funded by operating cash flow, and it
is anticipated that the remaining 1995 capital spending plan will be funded
accordingly. Excess funds provided from operations that are not required for
capital expenditures will be utilized to reduce outstanding debt.
 
  Plains paid a quarterly dividend of $.06 per share on March 31, 1995. On May
2, 1995, Plains declared a quarterly dividend of $.06 per share payable on June
30, 1995 to stockholders of record on June 13, 1995.
 
RESULTS OF OPERATIONS
 
 THREE MONTHS ENDED MARCH 31, 1995 VS. THREE MONTHS ENDED MARCH 31, 1994
 
  Increased production for the first three months of 1995, accompanied by
higher oil prices, resulted in record first quarter revenues for Plains.
Earnings were down 39% primarily due to higher exploration costs, interest and
depletion charges, income taxes and increased production costs due to expanded
operations.
 
  Revenues for the first quarter were $18.6 million, 15% over first quarter
1992 revenues of $16.2 million. This increase was attributable to a 24% rise in
production, on a barrel of oil equivalent basis, and a 36% increase in average
oil prices.
 
  Production and average sales prices during the periods presented were as
follows:
 
<TABLE>
<CAPTION>
                                                                      THREE
                                                                  MONTHS ENDED
                                                                    MARCH 31,
                                                                  -------------
                                                                   1995   1994
                                                                  ------ ------
   <S>                                                            <C>    <C>
   Natural gas production (Bcf)..................................    7.4    6.1
   Average price per Mcf......................................... $ 1.67 $ 2.08
   Oil production (MBbls)........................................    405    298
   Average price per barrel...................................... $15.51 $11.40
</TABLE>
 
  Natural gas revenues of $12.3 million for the current quarter were down 3%
from the first quarter of 1994. Average natural gas prices declined $.41 per
Mcf (20%), offsetting a 1.3 Bcf increase in natural gas volumes sold. Under a
seasonal pricing contract for natural gas effective for 1995, Plains realized
during the first quarter an average wellhead price of $1.87 per MMBtu from
Plains' principal purchaser for 6.6 Bcf sold from the Hugoton Field in
southwestern Kansas. Plains will receive $1.60 per MMBtu at the wellhead from
its principal purchaser under the first tier pricing of its contract for the
months of April through September and an anticipated weighted average of $2.05
per MMBtu for the fourth quarter of 1995. The balance of Plains' Hugoton Field
natural gas production, including production sold to its principal purchaser
under the second tier, will be priced on a spot market basis. Natural gas
production from the remainder of Plains' natural gas producing properties is
sold to various purchasers under spot sales and limited-term contracts of up to
one year. Spot market sales are burdened with additional gathering, processing,
transportation and marketing charges, ranging from $.15 to $.40 per MMBtu in
the Rocky Mountain and Mid-continent areas.
 
  First quarter oil revenues increased 85% to a record $6.3 million as compared
to $3.4 million for the same period in 1994. A 36% increase in oil production
was directly attributable to the success of Plains' 1994 exploration and
exploitation program and acquisitions of oil properties. Oil revenues were also
enhanced by a $4.11 per barrel (36%) increase in average oil prices for the
first quarter of 1995 from 1994.
 
  Operating expenses for the first quarter of 1995 of $16.6 million increased
24% from $13.4 million for the same period in 1994. In addition to impacting
revenues, property acquisitions made in 1994 and the first quarter of 1995,
combined with the addition of new wells on production and higher exploration
costs, directly influenced this increase.
 
                                      105
<PAGE>
 
  Production expenses, including lease operating costs, production and property
taxes, transportation and processing fees and net profits payments, increased
12% for the first quarter as compared to the same period in 1994. The increase
relates to the producing properties added through acquisitions, exploration and
exploitation activities. Production expenses, or lifting costs, approximated
$4.53 per barrel of oil equivalent for the first quarter of 1995 compared to
$5.01 per barrel of oil equivalent for 1994. As of March 31, 1995, there were
no known environmental or other regulatory matters related to Plains'
operations which would result in a material expense to Plains. No significant
environmental costs have been incurred or accrued through the periods presented
in this report.
 
  General and administrative expense increased approximately 12% from the first
quarter of 1994. This increase was attributable principally to consulting and
contract services expenses.
 
  Depreciation, depletion and amortization increased by approximately 12% in
the first quarter of 1995 over the prior year primarily due to sales volume
increases. However, reserve increases recognized within the past year favorably
reduced the weighted average depletion rate for Plains' oil and natural gas
properties from $3.21 per barrel of oil equivalent in the first quarter of 1994
to $2.83 per barrel of oil equivalent for 1995.
 
  Exploration costs were higher principally due to a $600,000 charge for an
unsuccessful exploratory well in the Patterson Deep Prospect of St. Mary
Parish, Louisiana.
 
  Interest expense increases were the direct result of higher debt balances
associated with the financing of an acquisition in November 1994.
 
  Plains' effective tax rates were 38% and 28% for the first quarter of 1995
and 1994, respectively. The 1994 rate incorporates the benefit of the existing
tax loss carryforwards being utilized in conjunction with the accounting for
income taxes. The current income tax provision is directly attributable to
earnings taxable under the federal alternative minimum tax and state income
taxes.
 
 1994 VS. 1993 AND 1993 VS. 1992
 
  During 1994, Plains generated net earnings of $6.6 million ($.68 per share)
compared to $1.7 million ($.18 per share) in 1993. In an effort to improve
profitability, Plains concentrated its efforts on improving the efficiency of
field operations while simultaneously reducing costs. Lower production and
exploration operating costs in 1994 offset increases in depreciation, depletion
and amortization expense and in general and administrative expenses. Net
earnings in 1993 were impacted by a $9.3 million impairment charge on certain
properties and a net credit of $1.3 million derived from two mandatory
accounting changes.
 
  Revenues for 1994 were $62 million, 4% lower than 1993 revenues of $64
million, primarily due to lower average natural gas and oil prices. Revenues
for 1993 increased 10% over 1992 as a result of higher volumes sold and
increased average gas prices. Natural gas revenues represented nearly 72% of
Plains' total revenues for 1994 and 1993.
 
  Natural gas revenues declined 4% to $44 million from $46 million in 1993
principally due to declining prices. Average natural gas prices for 1994 ranged
from $2.08 per Mcf in the first quarter to $1.74 in the fourth quarter,
resulting in average prices for the year of $1.86, down $.08, or 4%, from 1993.
Average prices for 1993 were up $.11 per Mcf from 1992.
 
  One-half of Plains' total natural gas revenues in 1994 were received from
Plains' principal purchaser for sales from the Hugoton Field in southwestern
Kansas and the Niobara area of northeastern Colorado. Plains received a
wellhead price of $2.00 MMBtu from this purchaser for the five months of
January through March, and November and December 1994. For the months of April
through October 1994, Plains received $1.80 and $1.75 per MMBtu at the wellhead
for the Hugoton Field and the Niobrara area, respectively. Under a two-tier
seasonal pricing contract effective for 1995, Plains will receive a weighted
average wellhead price of $1.80 per MMBtu on net sales volumes of 14 Bcf and
spot market prices on another 5 Bcf (net). In addition to the 1994 negotiated
permanent release of Hugoton Field wells connected to company-owned gathering
lines, an additional 37 wells were released for 1995. Production from these
wells will be sold on the spot market. Negotiations with the purchaser for 1996
prices will commence in late 1995.
 
                                      106
<PAGE>
 
  Wellhead prices received by Plains are not reduced by transportation and
marketing charges, whereas spot market sales by Plains are reduced by these
additional costs. These charges currently range from $.15 to $.40 per MMBtu in
the Rocky Mountain and Mid-continent areas. The balance of Plains' gas supplies
are sold to various purchasers under percentage of proceeds, short-term or spot
sales contracts.
 
  Natural gas production volumes of 23.9 Bcf sold in 1994 increased 1% over
1993 volumes of 23.8 Bcf. This nominal increase was attributed to constraints
on the principal purchaser's gathering system in the Hugoton Field for the
first quarter of 1994 and curtailment of production due to low prices during
the third quarter of 1994.
 
  Oil revenue of $17 million declined 5% from 1993 primarily due to a 6%
decline in average prices. Oil revenues of $18 million for 1993 declined 4% as
compared to 1992 oil revenues. Average oil prices realized during 1994 were at
a five-year average low of $13.91 per barrel, in comparison to $14.83 in 1993
and $18.20 in 1992. Oil production of 1.2 million barrels for 1994 was
comparable to 1993. However, due to the acquisition of primarily oil properties
in November 1994, average daily production by December 31, 1994 was 4,602
barrels, an increase of 34% from the beginning of 1994.
 
  Operating expenses for 1994 were relatively unchanged as compared with 1993,
excluding the $9.3 million impairment charge in 1993. Operating expense in
1993, exclusive of the impairment charge, was 14% over 1992 due to increased
lease operating costs and higher depreciation, depletion and amortization
charges associated with acquired properties.
 
  Production costs, including lease operating costs, production and property
taxes, transportation and processing fees and net profits payments, declined
$2.6 million to $24.7 million in 1994, a 10% decrease from 1993. Production
costs for 1994 approximated $4.73 per barrel of oil equivalent compared to
$5.28 per barrel of oil equivalent in 1993 and $5.48 per barrel of oil
equivalent in 1992.
 
  A decline in lease operating costs of 14% from 1993 levels was directly
attributable to Plains' program to improve operating efficiencies, dispose of
marginally economic wells and reduce costs, particularly with respect to oil
field operations. Lease operating costs for 1993 were 9% over 1992 due to
increased operating costs associated with acquisitions, drilling programs and
production workovers and increased transportation and processing costs on spot
sales of natural gas.
 
  Production and property taxes increased 10% in 1994 over the prior year.
Production taxes for 1994 decreased 6% due to lower revenues. Production taxes
for 1993 were at a comparable level to 1992. In 1994, conversely, property
taxes consisting principally of ad valorem taxes increased 31% over 1993. This
increase was primarily attributable to rising rates and valuation methods
utilized by Kansas tax authorities for the Hugoton Field properties.
 
  Transportation and processing costs decreased 6% in 1994 from 1993 due to
lower average charges of $.10 to $.15 per MMBtu related to spot market sales.
Increased spot market sales volumes in 1993 resulted in a 41% increase in
transportation and processing costs over 1992. Lower natural gas sales (down
7%) and an 11% decline in average prices received for production from Oklahoma
properties resulted in a 32% decline in net profits expense in 1994 as compared
to 1993. In 1993, natural gas sales from these same properties were higher as
compared to 1992 resulting in an increase in net profits expense of 4% above
1992.
 
  Consistent with industry practices, certain general and administrative costs
attributed directly to other operating expense classifications of lease
operations, exploration and transportation were reclassified to the respective
operating expense categories for the years 1994, 1993 and 1992. Employee
payroll expenses declined by 10% in 1994 from 1993 as a result of a 14% staff
reduction in 1993. After reclassifications of $2.3 million and $3.4 million for
1994 and 1993, respectively, to the operating expense categories, general and
administrative costs were approximately $935,000, or 15%, above 1993, primarily
due to higher costs related to employee benefit plans. Termination of an
administrative overhead sharing arrangement in mid-1992 and reduction of
operating overhead reimbursement attributed to properties sold caused 1993
general and administrative costs to increase 15% above 1992.
 
                                      107
<PAGE>
 
  Depreciation, depletion and amortization increased by 13% in 1994 primarily
due to an 11% increase in depletion rates over 1993. Depletion expenses for
1993 increased one-third over 1992. Higher cost-basis oil properties acquired
in previous years and revisions of oil reserves in 1993 and 1992 caused
depletion rates to increase for both periods. As recognition of the excess cost
basis over market value of certain Permian Basin properties in 1993, Plains
reduced the depletable basis through the recognition of an impairment provision
of $9.3 million.
 
  Exploration expenses consisting of unsuccessful exploration drilling, seismic
costs and lease impairments and rentals were 38% lower in 1994 than in 1993,
which, in turn, was 5% lower than 1992 due to reduced exploration activities.
 
  Borrowings for property acquisitions in the latter half of 1994 and
increasing interest rates resulted in higher interest expense than in 1993.
Interest rates and debt balances were lower in 1993 than in 1992.
 
  Other income was generated principally from third party utilization of
Plains' gathering and automation systems in the Hugoton Field. Restructuring
and staff reduction costs and unsuccessful acquisition expenses contributed to
an increase in other expenses in 1993.
 
  Effective January 1, 1993, Plains adopted the Financial Accounting Standards
Board Statement No. 106 on accounting for postretirement benefits other than
pensions. As a result of this adoption, Plains recognized a one-time,
cumulative charge of approximately $800,000 (pretax) in 1993 (see Note Five of
the Notes to Plains' Consolidated Financial Statements for periods ended
December 31, 1994, included herein).
 
  Plains' effective income tax rates were considerably below the statutory rate
primarily due to the benefit of Plains' tax loss carryforwards. Plains adopted
Statement of Financial Accounting Standards No. 109, "Accounting for Income
Taxes," effective January 1, 1993. A one-time, cumulative benefit of $2 million
for the effect of the accounting change on prior years was recognized in 1993
(see Notes One and Four to the Notes to Plains' Consolidated Financial
Statements for periods ended December 31, 1994, included herein).
 
                                      108
<PAGE>
 
                        INDEX TO CONSOLIDATED FINANCIAL
                             STATEMENTS OF BARRETT
 
<TABLE>
<S>                                                                         <C>
Consolidated Condensed Balance Sheets at September 30, 1994 and March 31,
 1995 (Unaudited).........................................................   F-2
Consolidated Condensed Statements of Income for Three Months Ended March
 31, 1994 and 1995 (Unaudited)............................................   F-3
Consolidated Condensed Statements of Income for Six Months Ended March 31,
 1994 and 1995 (Unaudited)................................................   F-4
Consolidated Condensed Statements of Cash Flows for Six Months Ended March
 31, 1994 and 1995 (Unaudited)............................................   F-5
Notes to Consolidated Condensed Financial Statements (March 31, 1995)
 (Unaudited)..............................................................   F-6
Report Of Independent Public Accountants..................................   F-7
Consolidated Balance Sheets at September 30, 1993 and 1994................   F-8
Consolidated Statements of Income for each of the three years in the
 period ended September 30, 1994..........................................   F-9
Consolidated Statements of Stockholders' Equity for each of the three
 years in the period ended September 30, 1994.............................  F-10
Consolidated Statements of Cash Flows for each of the three years in the
 period ended September 30, 1994..........................................  F-11
Notes to the Consolidated Financial Statements............................  F-12
Supplemental Oil And Gas Information......................................  F-21
Report Of Independent Public Accountants..................................  F-24
Schedule II: Amounts Receivable from Related Parties......................  F-25
Schedule V: Property, Plant and Equipment.................................  F-26
Schedule VI: Accumulated Depreciation, Depletion, Amortization and
 Impairment of Property, Plant and Equipment..............................  F-27
Schedule VIII: Valuation and Qualifying Accounts and Reserves.............  F-28
Schedule X: Supplemental Income Statement Information.....................  F-29
</TABLE>
 
                                      F-1
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                     CONSOLIDATED CONDENSED BALANCE SHEETS
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                      SEPTEMBER 30, MARCH 31,
                                                          1994         1995
                                                      ------------- ----------
                                                                    (UNAUDITED)
<S>                                                   <C>           <C>
                       ASSETS
                       ------
Current assets:
  Cash and cash equivalents..........................   $  7,760     $ 11,047
  Short-term investments.............................      1,970          --
  Receivables........................................     18,826       22,071
  Other current assets...............................        264          212
                                                        --------     --------
    Total current assets.............................     28,820       33,330
Net property and equipment...........................     76,925       98,360
Other assets.........................................        147          150
                                                        --------     --------
                                                        $105,892     $131,840
                                                        ========     ========
        LIABILITIES AND STOCKHOLDERS' EQUITY
        ------------------------------------
Current liabilities:
  Accounts payable...................................   $ 20,371     $  9,115
  Amounts payable to oil and gas property owners.....     11,560       15,440
  Accrued and other liabilities......................      1,089        2,162
                                                        --------     --------
    Total current liabilities........................     33,020       26,717
Long-term debt.......................................        --        31,000
Stockholders' equity:
  Preferred stock, $.001 par value: 1,000,000 shares
   authorized, none outstanding......................        --           --
  Common stock, $.01 par value: 17,000,000 shares
   authorized; 11,900,310 issued (11,845,083 at
   September 30, 1994)...............................        118          119
  Additional paid-in capital.........................     58,992       59,132
  Retained earnings..................................     13,762       14,872
                                                        --------     --------
    Total stockholders' equity.......................     72,872       74,123
                                                        --------     --------
                                                        $105,892     $131,840
                                                        ========     ========
</TABLE>
 
                            See accompanying notes.
 
                                      F-2
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                  CONSOLIDATED CONDENSED STATEMENTS OF INCOME
                                  (UNAUDITED)
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                           THREE MONTHS ENDED
                                                          ---------------------
                                                          MARCH 31,  MARCH 31,
                                                             1994       1995
                                                          ---------- ----------
<S>                                                       <C>        <C>
Revenues:
  Oil and gas production................................. $    4,943 $    6,346
  Trading revenues.......................................      4,337      7,788
  Revenue from gas gathering.............................         87        291
  Interest income........................................        232        115
  Other income...........................................         44          5
                                                          ---------- ----------
                                                               9,643     14,545
Operating expenses:
  Lease operating expense................................        802      1,456
  Cost of trading........................................      4,150      7,452
  Depreciation, depletion and amortization...............      1,808      3,038
  General and administrative.............................      1,158      1,358
  Interest expense.......................................          4        319
                                                          ---------- ----------
                                                               7,922     13,623
                                                          ---------- ----------
Income for the period before income taxes................      1,721        922
Provision for income taxes...............................         34         19
                                                          ---------- ----------
Net income for the period................................ $    1,687 $      903
                                                          ========== ==========
Net income per common share and common share equivalent.. $      .14 $      .07
                                                          ========== ==========
Weighted average number of shares of common stock and
 common stock equivalents................................ 11,922,952 12,109,515
                                                          ========== ==========
</TABLE>
 
 
                            See accompanying notes.
 
                                      F-3
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                  CONSOLIDATED CONDENSED STATEMENTS OF INCOME
                                  (UNAUDITED)
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                            SIX MONTHS ENDED
                                                          ---------------------
                                                          MARCH 31,  MARCH 31,
                                                             1994       1995
                                                          ---------- ----------
<S>                                                       <C>        <C>
Revenues:
  Oil and gas production................................. $    9,416 $   10,343
  Trading revenues.......................................      9,398     18,520
  Revenue from gas gathering.............................        137        442
  Interest income........................................        472        205
  Other income...........................................         44         41
                                                          ---------- ----------
                                                              19,467     29,551
Operating expenses:
  Lease operating expense................................      1,742      2,390
  Cost of trading........................................      8,954     17,869
  Depreciation, depletion and amortization...............      3,485      4,806
  General and administrative.............................      2,423      2,983
  Interest expense.......................................          4        370
                                                          ---------- ----------
                                                              16,608     28,418
                                                          ---------- ----------
Income for the period before income taxes................      2,859      1,133
Provision for income taxes...............................         57         23
                                                          ---------- ----------
Net income for the period................................ $    2,802 $    1,110
                                                          ========== ==========
Net income per common share and common share equivalent.. $      .23 $      .09
                                                          ========== ==========
Weighted average number of shares of common stock and
 common stock equivalents................................ 11,909,878 12,105,999
                                                          ========== ==========
</TABLE>
 
 
 
                            See accompanying notes.
 
                                      F-4
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                                  (UNAUDITED)
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                             SIX MONTHS ENDED
                                                            --------------------
                                                            MARCH 31,  MARCH 31,
                                                              1994       1995
                                                            ---------  ---------
<S>                                                         <C>        <C>
Cash flows from operations:
  Net income............................................... $  2,802   $  1,110
  Adjustments needed to reconcile to net cash flow provided
   by operations:
    Depreciation, depletion, and amortization..............    3,485      4,806
    Reversal of gas trading allowance......................       92        --
    Change in other assets.................................        4         58
    Change in current assets and liabilities:
      Decrease (increase) in current receivables...........      351     (1,248)
      Decrease in other current assets.....................      180         52
      Increase (decrease) in accounts payable..............    2,438       (227)
      Increase in accrued and other liabilities............      147      1,073
                                                            --------   --------
Net cash flow provided by operations.......................    9,499      5,508
                                                            --------   --------
Cash flows from investing activities:
  Maturity of short-term investments.......................    5,952      1,970
  Purchase of short-term investments.......................   (7,428)       --
  Proceeds from sale of oil and gas properties.............      387        --
  Acquisition of property and equipment....................  (14,791)   (34,361)
  Other....................................................       40         55
                                                            --------   --------
Net cash flow used in investing activities.................  (15,840)   (32,336)
                                                            --------   --------
Cash flows from financing activities:
  Proceeds from issuance of common stock...................      105        141
  Decrease (increase) in cash from operating oil and gas
   properties..............................................      790     (1,026)
  Borrowings on line of credit.............................      --      31,000
                                                            --------   --------
Net cash flow provided by financing activities.............      895     30,115
                                                            --------   --------
(Decrease) increase in cash and cash equivalents...........   (5,446)     3,287
Cash and cash equivalents at beginning of period...........   33,187      7,760
                                                            --------   --------
Cash and cash equivalents at end of period................. $ 27,741   $ 11,047
                                                            ========   ========
</TABLE>
 
                            See accompanying notes.
 
                                      F-5
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
                                 MARCH 31, 1995
                                  (UNAUDITED)
 
1. UNAUDITED CONSOLIDATED CONDENSED FINANCIAL STATEMENTS
 
  In the opinion of management, the accompanying unaudited consolidated
condensed financial statements contain all adjustments necessary to present
fairly the financial position of Barrett as of March 31, 1995 and the results
of operations and cash flows for the periods presented. All such adjustments
are of a normal recurring nature. The results of operations for the periods
presented are not necessarily indicative of the results for the full year.
 
  The accounting policies followed by Barrett are set forth in Note 1 to
Barrett's financial statements in Form 10-K for the year ended September 30,
1994. It is suggested that these financial statements be read in conjunction
with the financial statements and notes included in the Form 10-K.
 
2. INCOME TAXES
 
  The net deferred tax assets of Barrett were $2,688,000 and $1,151,000 as of
September 30, 1993 and 1994, respectively. In order to reflect the amounts not
expected to be utilized before the expiration of available net operating loss
carryforwards and due to the effects of anticipated exploratory drilling costs,
a valuation allowance equal to the entire net deferred tax asset was provided
at both September 30, 1993 and 1994.
 
  For the six months ended March 31, 1995, Barrett has used its estimated
effective tax rate to compute the provision for income taxes as Barrett does
not believe it can reliably estimate its taxable income with any degree of
precision for the current fiscal year. The estimated tax rate for the quarter
and six months ended March 31, 1995 is approximately two percent.
 
3. LONG-TERM DEBT
 
  As of March 31, 1995, the commitment amount of Barrett's reserve-based line
of credit with a bank was $80 million and the borrowing base was $40 million.
In order to reduce the commitment fees, Barrett voluntarily requested that the
maximum borrowing be limited to $35 million. At March 31, 1995, $31 million was
outstanding on the line of credit.
 
4. CAPITALIZED INTEREST
 
  During the six months ended March 31, 1995, Barrett borrowed against its line
of credit to fund its oil and gas development and the construction of a gas
plant and a gathering system extension. Barrett capitalizes interest costs on
amounts expended on assets during the period in which activities are occurring
to place the asset in service. Excluded from interest capitalization are
amounts spent to develop properties included in the full cost center of oil and
gas properties. The gas plant and gathering system extension were placed in
service on December 1, 1994 while development of certain unevaluated oil and
gas properties continued throughout the six month period.
 
  Total interest costs incurred for the quarter ended March 31, 1995 were
$470,000. Of this amount $151,000 was capitalized to the specific projects and
$319,000 was recorded as interest expense. For the six month period $269,000
was capitalized and $370,000 was recorded as interest expense.
 
                                      F-6
<PAGE>
 
                         REPORT OF ARTHUR ANDERSEN LLP
 
                         INDEPENDENT PUBLIC ACCOUNTANTS
 
The Board of Directors
Barrett Resources Corporation
Denver, Colorado 80202
 
  We have audited the accompanying consolidated balance sheets of Barrett
Resources Corporation as of September 30, 1994 and 1993, and the related
consolidated statements of income, stockholders' equity and cash flows for each
of the three years in the period ended September 30, 1994. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.
 
  We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of
material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant
estimates made by management, as well as evaluating the overall financial
statement presentation. We believe that our audits provide a reasonable basis
for our opinion.
 
  In our opinion, the financial statements referred to above present fairly, in
all material respects, the consolidated financial position of Barrett Resources
Corporation at September 30, 1994 and 1993, and the consolidated results of its
operations and its cash flows for each of the three years in the period ended
September 30, 1994, in conformity with generally accepted accounting
principles.
 
  As explained in Note 1 to the consolidated financial statements, effective
October 1, 1991, the Company changed its method of accounting for income taxes.
 
                                          Arthur Andersen LLP
 
Denver, Colorado
December 8, 1994
 
                                      F-7
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                          CONSOLIDATED BALANCE SHEETS
 
                          SEPTEMBER 30, 1993 AND 1994
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                            ASSETS                              1993     1994
                            ------                             ------- --------
<S>                                                            <C>     <C>
Current assets:
  Cash and cash equivalents................................... $33,187 $  7,760
  Short-term investments......................................   1,984    1,970
  Receivables.................................................  17,762   18,826
  Other current assets........................................     367      264
                                                               ------- --------
    Total current assets......................................  53,300   28,820
Net property and equipment (full cost method).................  36,267   76,925
Other assets..................................................   1,173      147
                                                               ------- --------
                                                               $90,740 $105,892
                                                               ======= ========
<CAPTION>
             LIABILITIES AND STOCKHOLDERS' EQUITY
             ------------------------------------
<S>                                                            <C>     <C>
Current liabilities:
  Accounts payable............................................ $10,432 $ 20,371
  Amounts payable to oil and gas property owners..............  11,130   11,560
  Accrued and other liabilities...............................     986    1,089
                                                               ------- --------
    Total current liabilities.................................  22,548   33,020
Stockholders' equity:
  Preferred stock, $.001 par value: 1,000,000 shares
   authorized, none outstanding...............................     --       --
  Common stock, $.01 par value: 17,000,000 shares authorized,
   11,845,083 outstanding (11,707,316 at September 30, 1993)..     117      118
  Additional paid-in capital..................................  58,752   58,992
  Retained earnings...........................................   9,323   13,762
                                                               ------- --------
    Total stockholders' equity................................  68,192   72,872
                                                               ------- --------
                                                               $90,740 $105,892
                                                               ======= ========
</TABLE>
 
 
                            See accompanying notes.
 
                                      F-8
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                       CONSOLIDATED STATEMENTS OF INCOME
 
                 YEARS ENDED SEPTEMBER 30, 1992, 1993 AND 1994
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                         1992    1993    1994
                                                        ------- ------- -------
<S>                                                     <C>     <C>     <C>
Revenues:
  Oil and gas production..............................  $ 6,626 $14,976 $17,577
  Trading revenues....................................   16,726  26,357  22,443
  Revenue from gas gathering..........................      279     271     252
  Interest income.....................................      600     498     891
  Other income........................................       54     584      89
                                                        ------- ------- -------
                                                         24,285  42,686  41,252
Operating expenses:
  Lease operating expenses............................    1,397   2,725   3,535
  Depreciation, depletion and amortization............    3,259   6,130   6,915
  Cost of trading.....................................   16,601  25,343  21,577
  General and administrative..........................    2,062   2,565   4,713
  Interest expense....................................       26      13       6
                                                        ------- ------- -------
                                                         23,345  36,776  36,746
                                                        ------- ------- -------
Income before income taxes and cumulative effect of
 change in method of accounting for income taxes......      940   5,910   4,506
Provision for income taxes............................       18     154      67
                                                        ------- ------- -------
Income before cumulative effect of change in method of
 accounting for income taxes..........................      922   5,756   4,439
Cumulative effect of change in method of accounting
 for income taxes.....................................      583     --      --
                                                        ------- ------- -------
Net income............................................  $ 1,505 $ 5,756 $ 4,439
                                                        ======= ======= =======
Net income per common share and common share
 equivalent before change in method of accounting for
 income taxes.........................................  $   .09 $   .53 $   .37
                                                        ======= ======= =======
Net income per common share and common share
 equivalent--cumulative effect........................  $   .06 $   --  $   --
                                                        ======= ======= =======
Net income per common share and common share
 equivalent...........................................  $   .15 $   .53 $   .37
                                                        ======= ======= =======
</TABLE>
 
 
                            See accompanying notes.
 
                                      F-9
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
 
                 YEARS ENDED SEPTEMBER 30, 1992, 1993 AND 1994
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                                                NOTES
                                ADDITIONAL                    RECEIVABLE      TOTAL
                         COMMON  PAID-IN   TREASURY RETAINED     FROM     STOCKHOLDERS'
                         STOCK   CAPITAL    STOCK   EARNINGS STOCKHOLDERS    EQUITY
                         ------ ---------- -------- -------- ------------ -------------
<S>                      <C>    <C>        <C>      <C>      <C>          <C>
Balance, October 1,
 1991...................  $ 99   $40,521    $ --    $ 2,062     $(651)       $42,031
Exercise of stock
 options................   --         26      --        --        --              26
Purchase of treasury
 stock..................   --        --      (247)      --        --            (247)
Retirement of treasury
 stock..................   --       (247)     247       --        --             --
Retirement of notes
 receivable from
 stockholders...........    (2)     (649)     --        --        651            --
Net income for the year
 ended September 30,
 1992...................   --        --       --      1,505       --           1,505
                          ----   -------    -----   -------     -----        -------
Balance, September 30,
 1992...................    97    39,651      --      3,567       --          43,315
Exercise of stock
 options................   --        220      --        --        --             220
Issuance of common
 stock..................    20    18,881      --        --        --          18,901
Net income for the year
 ended September 30,
 1993...................   --        --       --      5,756       --           5,756
                          ----   -------    -----   -------     -----        -------
Balance, September 30,
 1993...................   117    58,752      --      9,323       --          68,192
Exercise of stock
 options................     2       791     (474)      --        --             319
Purchase of treasury
 stock..................   --        --       (78)      --        --             (78)
Retirement of treasury
 stock..................    (1)     (551)     552       --        --             --
Net income for the year
 ended September 30,
 1994...................   --        --       --      4,439       --           4,439
                          ----   -------    -----   -------     -----        -------
Balance, September 30,
 1994...................  $118   $58,992    $ --    $13,762     $ --         $72,872
                          ====   =======    =====   =======     =====        =======
</TABLE>
 
 
                            See accompanying notes.
 
                                      F-10
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
 
                 YEARS ENDED SEPTEMBER 30, 1992, 1993 AND 1994
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                     1992      1993      1994
                                                   --------  --------  --------
<S>                                                <C>       <C>       <C>
Cash flows from operations:
  Net income.....................................  $  1,505  $  5,756  $  4,439
  Adjustments needed to reconcile to net cash
   flow provided by operations:
    Depreciation, depletion and amortization.....     3,259     6,130     6,915
    Unrealized (gain) loss on trading............       268      (368)      100
    Decrease in deferred income taxes............      (583)      --        --
    Change in other assets.......................        27        (2)       10
    Change in current assets and liabilities:
      Increase in accounts receivables...........    (2,594)     (792)   (1,968)
      Increase (decrease) in other current
       assets....................................       (39)     (247)      102
      Increase (decrease) in accounts payable....     2,654      (165)    2,099
      Increase (decrease) in accrued and other
       liabilities...............................       473      (455)        3
                                                   --------  --------  --------
Net cash flow provided by operations.............     4,970     9,857    11,700
                                                   --------  --------  --------
Cash flows from investing activities:
  Proceeds from sale of oil and gas properties...       920    15,909       387
  Purchase of short-term investments.............      (499)   (1,984)  (15,290)
  Maturity of short-term investments.............     2,500       499    15,304
  Acquisition of property and equipment..........   (11,883)  (20,342)  (38,972)
  Other..........................................       204        69        87
                                                   --------  --------  --------
Net cash flow used in investing activities.......    (8,758)   (5,849)  (38,484)
                                                   --------  --------  --------
Cash flows from financing activities:
  Proceeds from issuance of common stock.........        12    19,121       319
  Purchase of treasury stock.....................      (247)      --        (78)
  Borrowing under line of credit.................       --      1,300       --
  Payments on line of credit.....................       --     (1,300)      --
  Increase (decrease) in cash held from operating
   oil and gas properties........................    (1,528)     (762)    1,116
                                                   --------  --------  --------
Net cash flow provided by (used in) financing
 activities......................................    (1,763)   18,359     1,357
                                                   --------  --------  --------
(Decrease) increase in cash and cash equivalents.    (5,551)   22,367   (25,427)
Cash and cash equivalents at beginning of year...    16,371    10,820    33,187
                                                   --------  --------  --------
Cash and cash equivalents at end of year.........  $ 10,820  $ 33,187  $  7,760
                                                   ========  ========  ========
</TABLE>
 
                            See accompanying notes.
 
                                      F-11
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
 Consolidation:
 
  The consolidated financial statements include the accounts of the Company and
its subsidiaries, all of which are wholly-owned. All significant intercompany
transactions have been eliminated in consolidation.
 
 Partnerships:
 
  The consolidated financial statements include the Company's proportionate
share of the assets, liabilities, revenues and expenses of its oil and gas
partnership interests.
 
 Cash and cash equivalents:
 
  Cash in excess of daily requirements is invested in money market accounts and
commercial paper with maturities of three months or less. Such investments are
deemed to be cash equivalents for purposes of the statement of cash flows.
 
 Short-term investments:
 
  Short-term investments consist of commercial paper and government securities
with original maturities greater than three months. Such investments are valued
at cost which approximates market.
 
 Oil and gas properties:
 
  The Company utilizes the full cost method of accounting for oil and gas
properties whereby all productive and nonproductive costs paid to third parties
that are incurred in connection with the acquisition, exploration and
development of oil and gas reserves are capitalized. No gains or losses are
recognized upon the sale, conveyance or other disposition of oil and gas
properties except in extraordinary transactions.
 
  Capitalized costs are accumulated on a country-by-country basis subject to a
cost center ceiling and amortized using the unit-of-production method. The
Company presently has only one cost center since all of its properties are
located in the United States. Amortizable costs include developmental drilling
in progress as well as estimates of future development costs of proved reserves
but exclude the costs of unevaluated oil and gas properties. Accumulated
depreciation and amortization is written off as assets are retired.
Amortization equaled approximately $4.16, $4.49 and $4.56 per BOE ($.69, $.75,
and $.76 per Mcfe) for the years ended September 30, 1994, 1993 and 1992,
respectively.
 
  The Company acquires nonproducing acreage to be developed primarily through
industry partners. The cost of these leases is included in unevaluated oil and
gas property costs recorded at the lower of cost or fair market value.
 
  The Company operates many of the wells in which it owns an economic interest.
The operating agreements for these activities provide for a fee structure to
allow the Company to recover a portion of its direct and overhead charges
related to its operating activities. The fees collected under the operating
agreements are recorded as a reduction of general and administrative expenses.
Any amounts collected from a sale of oil and gas interests or earned as a
result of assembling oil and gas drilling activities are applied to reduce the
book value of oil and gas properties.
 
                                      F-12
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
 Other property and equipment:
 
  Other property and equipment is recorded at cost. Renewals and betterments
which substantially extend the useful life of the assets are capitalized.
Maintenance and repairs are expensed when incurred. Depreciation is provided
using accelerated and straight-line methods over the estimated useful lives,
ranging from five to ten years, of the assets.
 
 Amounts payable to oil and gas property owners:
 
  Amounts payable to oil and gas property owners consist of cash calls from
working interest owners to pay for development costs of properties being
currently developed, production revenue that the Company, as operator, is
collecting and distributing to revenue interest owners and production revenue
taxes that the Company, as operator, has withheld for timely payment to the tax
agencies.
 
 Income taxes and change in accounting policy:
 
  During the fourth quarter of 1992, the Company adopted Statement of Financial
Accounting Standards (SFAS) No. 109, "Accounting for Income Taxes," effective
October 1, 1991. SFAS No. 109 requires the measurement of deferred tax assets
for deductible temporary differences and operating loss carryforwards and of
deferred tax liabilities for taxable temporary differences. Measurement of
current and deferred tax liabilities and assets is based on provisions of
enacted tax law; the effects of future changes in tax laws or rates are not
anticipated. Deferred tax assets primarily result from net operating loss
carryforwards and deferred tax liabilities from the recognition of
depreciation, depletion and amortization in different periods for financial
reporting and tax purposes. The adjustments to the October 1, 1991 balance
sheet to adopt SFAS No. 109 netted to $583,000. This amount is reflected in net
income as the cumulative effect of a change in accounting principle.
 
 Trading:
 
  The Company's business activities include buying and selling of natural gas.
The Company recognizes revenue and costs on gas trading transactions at the
point in time when gas is delivered to the purchaser.
 
 Hedging activities:
 
  The Company uses both commodity futures contracts and price swaps to hedge
the impact of price fluctuations on a portion of its production and trading
activities. The Company enters into a hedging position for specific
transactions that management deems expose the Company to an unacceptable market
price risk. If the Company enters into price swaps or commodities transactions
that do not correspond to scheduled physical transactions (scheduled physical
transactions include committed trading activities or production from producing
wells), the transactions would not qualify for hedge accounting. In that event
the Company will record the instruments at fair value and record gains and
losses as fair values fluctuate from time to time compared to cost.
 
  Gains or losses on hedging transactions are deferred until the physical
transaction occurs for financial reporting purposes. Deferred gains and losses
and unrealized gains and losses are evaluated in connection with the physical
transaction underlying the hedge position. Gains or losses on hedging
activities are recorded in the income statement as adjustments of the revenue
or cost of the underlying physical transaction. Hedging transactions are
reported as operating activities in the statements of cash flows.
 
  During 1994, the Company incurred a net cost of $713,000 to hedge the index
based price for 6.8 Bcf of gas purchased in various transactions for its gas
trading activities. These payments allowed the Company to
 
                                      F-13
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
purchase gas on a fixed price basis to satisfy fixed price sales commitments.
This hedging allowed the Company to avoid gas price fluctuations for the
related transactions so that the Company realized the gross profit margins
anticipated upon entering into the trading arrangements. This hedging cost is
included in the income statement as a component of "Cost of Trading." In
addition, the Company paid $65,000 to hedge the index based sales price for
920,000 mcf of its gas production. This cost is reported as a reduction of
production revenue.
 
  As of September 30, 1994, the Company held swap positions for 5.6 bcf of gas
(7.9 bcf at September 30, 1993) for periods through March 1996. The positions
are described as follows:
 
  A. The Company is the fixed price payor for 4.2 bcf of gas subsequent to
     September 30, 1994 at prices ranging from $1.60 to $2.10 per mcf for
     swap transactions that hedge trading arrangements in which the Company
     has agreed to sell gas at a fixed price and buy gas at an index price.
     The price swap allows the Company to convert the index price related to
     gas purchased to the equivalent of a fixed price. This hedge transaction
     eliminates the risk associated with price fluctuations by shifting the
     price risk to a counter party. As of September 30, 1993, the Company
     held such swap positions for 6.5 bcf of gas at prices ranging from $1.46
     to $2.10 per mcf.
 
  B. The Company will receive fixed prices ranging from $1.59 to $1.63 per
     mcf in swap transactions associated with 1.4 bcf of gas to be produced
     by the Company subsequent to September 30, 1994. As of September 30,
     1993, the Company held such positions for 460,000 mcf at prices ranging
     from $1.90 to $2.11 per mcf.
 
 Earnings per share:
 
  Per share amounts were computed using the weighted average number of shares
of common stock and common stock equivalents outstanding during each year:
1994--11,917,433; 1993--10,908,174; and 1992--9,732,818. Options to purchase
stock are included as common stock equivalents, when dilutive, using the
treasury stock method.
 
 Reclassification:
 
  Certain amounts in 1993 and 1992 have been reclassified to correspond to the
1994 presentation.
 
2. RECEIVABLES
 
<TABLE>
<CAPTION>
                                                                 1993    1994
                                                                ------- -------
                                                                (IN THOUSANDS)
      <S>                                                       <C>     <C>
      Oil and gas revenue receivable........................... $ 6,113 $ 6,496
      Joint interest billings..................................   9,018   8,622
      Trading receivables......................................   2,414   3,309
      Other accounts receivable................................     217     399
                                                                ------- -------
                                                                $17,762 $18,826
                                                                ======= =======
</TABLE>
 
  The Company's accounts receivable are primarily due from medium size oil and
gas entities in the Rocky Mountain region. Collection of joint interest
billings is generally secured by future production. The Company performs
periodic credit evaluations of customers purchasing production for which no
collateral is required. Historically, the Company has not experienced
significant losses related to these extensions of credit.
 
  As of September 30, 1994 and 1993 receivables are recorded net of allowance
for doubtful accounts of $43,000 and $44,000, respectively.
 
                                      F-14
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
3. PROPERTY AND EQUIPMENT
 
<TABLE>
<CAPTION>
                                                                 1993    1994
                                                                ------- -------
                                                                (IN THOUSANDS)
      <S>                                                       <C>     <C>
      Oil and gas properties, full cost method:
        Unevaluated costs, not being amortized................. $ 3,059 $ 8,043
        Evaluated costs........................................  49,151  88,436
      Construction in process, gas gathering system............     --    2,631
      Gas gathering systems....................................   2,808   3,118
      Furniture, vehicles and equipment........................   1,518   1,786
                                                                ------- -------
                                                                 56,536 104,014
      Less accumulated depreciation, depletion, amortization
       and impairment..........................................  20,269  27,089
                                                                ------- -------
                                                                $36,267 $76,925
                                                                ======= =======
</TABLE>
 
4. UNEVALUATED OIL AND GAS PROPERTY COSTS
 
  Unevaluated oil and gas property costs consist of the following:
 
<TABLE>
<CAPTION>
                                                  COSTS INCURRED DURING
                                         ---------------------------------------
                                         1989 1990 1991 1992 1993  1994   TOTAL
                                         ---- ---- ---- ---- ---- ------- ------
                                                     (IN THOUSANDS)
<S>                                      <C>  <C>  <C>  <C>  <C>  <C>     <C>
Acquisition costs....................... $93  $ 72 $ 89 $283 $189 $ 4,801 $5,527
Exploration costs....................... --     52   40  279  247   1,898  2,516
                                         ---  ---- ---- ---- ---- ------- ------
                                         $93  $124 $129 $562 $436 $ 6,699 $8,043
                                         ===  ==== ==== ==== ==== ======= ======
</TABLE>
 
  The unevaluated costs were incurred for properties which are being assembled
for sale to the industry and for projects which are being explored. The Company
anticipates that substantially all unevaluated costs will be recovered from
property sales or classified as evaluated costs within the next three years.
 
5. LONG-TERM DEBT
 
  The Company has a reserve-based line of credit with a bank which provides up
to $30,000,000 for a three year period ending July 31, 1996 with the
outstanding principal balance due on July 31, 2001. The amount actually
available to the Company under the line at any given time is limited to the
collateral value of proved reserves as determined by the lender. Based on the
lender's determination of collateral value, as of September 30, 1994 (which was
based on the September 30, 1993 reserve report), the Company has a net
borrowing limit of $17,500,000. In order to reduce the commitment fees, the
Company voluntarily requested that the Bank limit the maximum borrowing to
$1,000,000 through September 30, 1994. Subsequent to September 30, 1994, the
Company increased the maximum borrowing limit to $17,500,000. The lender is
currently reviewing the September 30, 1994 reserve report to determine current
collateral value. Interest accrues at a base rate of the bank's prime rate
(7.75 percent at September 30, 1994) for borrowings under the commitment up to
50 percent of the borrowing base plus a one-half of one percent per year
commitment fee on the daily average of the unborrowed amount. Once the
outstanding balance exceeds 50 percent of the borrowing base, the interest rate
on all borrowings increases to prime plus one-half of one percent. The line of
credit agreement prohibits the payment of dividends, borrowings, sale of
assets, loans to others, investment and merger activity without the prior
consent of the bank and requires the Company to maintain certain net worth
levels and interest coverage ratios. No amounts were outstanding under this
line of credit at year end.
 
 
                                      F-15
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
6. COMMON STOCK
 
  During the year ended September 30, 1993, the Company completed a public
offering of 2,000,000 shares of its common stock at a price to the public of
$10.25 per share. The net proceeds of the offering, after deducting all
associated costs, were $18,901,000.
 
  The Company has stock option plans under which options of the Company's
common stock may be granted to officers and employees of the Company or its
subsidiaries.
 
  Effective as of April 1, 1994, the board of directors approved the 1994 Stock
Option Plan. The Plan, as amended, provides for options to purchase 400,000
shares of the Company's common stock, and is subject to the approval of the
stockholders on or before March 31, 1995.
 
  At the annual meeting on June 16, 1993, the 1990 Stock Option Plan was
amended to increase the number of shares issuable pursuant to options from
400,000 to 600,000 shares. At the annual meeting on March 17, 1994 the 1990
Stock Option Plan was again amended to increase the number of shares issuable
pursuant to options from 600,000 to 775,000 shares. During 1992, the majority
of previously granted options were canceled and new options granted with an
exercise price of $4.25.
 
  At September 30, 1992, options to purchase 379,000 shares at prices ranging
from $3.625 to $5.125 per share with an aggregate price of $1,627,000 were
granted and outstanding, none of which were exercisable. At September 30, 1993,
options to purchase 357,000 shares at prices ranging from $3.875 to $12.125 per
share with an aggregate price of $1,851,000 were outstanding, 122,500 of which
were exercisable. During 1994, options to purchase 529,500 shares were granted
at prices ranging from $11.375 to $17.625. At September 30, 1994, options to
purchase 697,430 shares at prices ranging from $3.875 to $17.625 per share with
an aggregate price of $8,620,278 were outstanding 117,930 of which were
exercisable. During 1994, 176,070 options were exercised and 13,000 options
expired.
 
  The Company has a non-discretionary stock option plan under which options for
an aggregate of 100,000 shares of the Company's common stock may be granted to
non-employee directors. At September 30, 1993, options to purchase 10,000
shares at a price of $5.00 per share, an aggregate price of $50,000, were
outstanding, 7,000 of which were exercisable. At September 30, 1994, options to
purchase 60,000 shares at prices ranging from $5.00 to $17.625, an aggregate
exercise price of $641,000 were outstanding, 17,500 of which were exercisable.
As of September 30, 1994 no options have been exercised under the plan.
 
  During 1992, the Company repurchased 64,200 shares of its common stock for an
aggregate price of $247,000. During 1994, the Company repurchased 4,578 shares
of its common stock for an aggregate price of $78,000. These shares were
subsequently retired.
 
  In December, 1989, the Company made loans to finance the exercise of options
to purchase 199,250 shares, at an aggregate exercise price of $703,000, which
were expiring. The loans matured at the earlier of sale of the shares or
January 31, 1992. Of this amount, $52,000 was repaid prior to October 1, 1991.
The remaining $651,000 in loans matured in January 1992 and the Company retired
the stock held as collateral in full satisfaction of the loans.
 
                                      F-16
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
7. LEASES
 
  The minimum future payments under the terms of operating leases, principally
for office space, are as follows:
 
<TABLE>
<CAPTION>
                                                                  (IN THOUSANDS)
      <S>                                                         <C>
Year ended September 30, 
                1995.............................................     $  345
                1996.............................................        357
                1997.............................................        326
                1998.............................................        326
                1999.............................................        347
                                                                      ------
                                                                      $1,701
                                                                      ======
</TABLE>
 
  Rent expense was $326,000, $253,000 and $218,000 for the years ended
September 30, 1994, 1993 and 1992, respectively.
 
8. INCOME TAXES
 
  The provision for income taxes consists of the following:
 
<TABLE>
<CAPTION>
                                                          1992  1993     1994
                                                          ---- -------  -------
                                                             (IN THOUSANDS)
      <S>                                                 <C>  <C>      <C>
      Current:
        Federal.......................................... $ 18 $   154  $    67
        State............................................  --      --       --
                                                          ---- -------  -------
                                                            18     154       67
      Deferred:
        Federal..........................................  --    1,828    1,532
        State............................................  --      355        5
                                                          ---- -------  -------
                                                           --    2,183    1,537
                                                          ---- -------  -------
                                                            18   2,337    1,604
      Change in valuation allowance......................  --   (2,183)  (1,537)
                                                          ---- -------  -------
                                                          $ 18 $   154  $    67
                                                          ==== =======  =======
</TABLE>
 
  The difference between the provision for income taxes and the amounts which
would be determined by applying the statutory federal income tax rate to income
before provision for income taxes is analyzed below:
 
<TABLE>
<CAPTION>
                                                       1992    1993     1994
                                                       -----  -------  -------
                                                          (IN THOUSANDS)
<S>                                                    <C>    <C>      <C>
Tax by applying the statutory federal income tax rate
 to pretax accounting income.......................... $ 320  $ 2,009  $ 1,577
Increase (decrease) in tax from:
  Change in valuation allowance.......................  (322)  (2,183)  (1,537)
  State income taxes..................................   --       355        5
  Use of net operating loss carryforward..............   --       --       --
  Use of statutory depletion carryforward.............   --       --       --
  Alternative minimum tax--federal and state..........    18      --         8
  Other--net..........................................     2      (27)      14
                                                       -----  -------  -------
                                                       $  18  $   154  $    67
                                                       =====  =======  =======
</TABLE>
 
 
                                      F-17
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
  Long-term deferred tax assets (liabilities) are comprised of the following at
September 30, 1994 and 1993:
 
<TABLE>
<CAPTION>
                                                                1993     1994
                                                               -------  -------
                                                               (IN THOUSANDS)
<S>                                                            <C>      <C>
Deferred tax assets:
  Allowance for losses........................................ $   132  $   157
  Loss carryforwards..........................................   4,998    5,145
                                                               -------  -------
    Gross deferred tax assets.................................   5,130    5,302
Deferred tax liabilities:
  Deferred revenue--partnership activities....................  (2,069)    (912)
  Depreciation, depletion and amortization....................    (371)  (3,237)
  Capitalized interest on other assets........................      (2)      (2)
                                                               -------  -------
    Gross deferred tax liabilities............................  (2,442)  (4,151)
                                                               -------  -------
      Net deferred tax asset..................................   2,688    1,151
      Valuation allowance.....................................  (2,688)  (1,151)
                                                               -------  -------
                                                               $   --   $   --
                                                               =======  =======
</TABLE>
 
  The Company had taxable income or loss and book income before taxes for the
three years in the period ended September 30, 1994 as follows:
 
<TABLE>
<CAPTION>
                                                         1992     1993    1994
                                                        -------  ------- ------
<S>                                                     <C>      <C>     <C>
Taxable income (loss).................................. $(1,133) $10,161 $  481
Book income before taxes...............................     940    5,910  4,506
</TABLE>
 
  The primary difference between taxable income (loss) and book income before
taxes relates to the difference in treatment of oil and gas property costs for
tax purposes contrasted to the full cost method for book purposes.
 
  Valuation allowances of $1,151,000 and $2,688,000 were provided at September
30, 1994 and 1993, respectively, based on carryforward amounts which may not be
utilized before expiration and the possible effect of exploratory drilling
costs. The Company reduced the valuation allowance by $1,537,000 to recognize
the increased cash flow from proved oil and gas reserves added during the year
and a portion of its loss carryforward being used to reduce taxable income.
 
  The Company has the following net operating loss and investment tax credit
carryforwards available:
 
<TABLE>
<CAPTION>
                                                           NET
                                                        OPERATING INVESTMENT
      EXPIRATION YEAR                                     LOSS    TAX CREDIT
      ---------------                                   --------- ----------
                                                             (IN THOUSANDS)
      <S>                                               <C>       <C>        <C>
      1996.............................................  $   --      $ 21
      1997.............................................    4,325       62
      1998.............................................    4,673       54
      1999.............................................    1,051       59
      2000.............................................    1,510       19
      2001.............................................    1,794       10
      2002.............................................      335      --
      2007.............................................    1,446      --
                                                         -------     ----
          Total........................................  $15,134     $225
                                                         =======     ====
</TABLE>
 
 
                                      F-18
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
A substantial portion of the net operating losses were acquired in conjunction
with purchased operations.
 
  The 1990 public offering of common stock resulted in a change in the
Company's ownership as defined in Section 382 of the Internal Revenue Code. The
effect of this change in ownership limits the utilization of net operating
losses for income tax purposes to approximately $3,069,000 per year. Portions
of this $3,069,000 which are not used each year may be carried forward to
future years. As of September 30, 1994, the Company's cumulative Section 382
limitation is approximately $5,803,000.
 
9. SEGMENT INFORMATION
 
  The Company operates in two reportable segments; oil and gas exploration and
development and trading. The segment results are presented in the following
schedule:
 
<TABLE>
<CAPTION>
                           OIL &                     CONSOLIDATED
SEPTEMBER 30, 1994          GAS   TRADING  CORPORATE    TOTAL
- ------------------        ------- -------  --------- -----------
                                     (IN THOUSANDS)
<S>                       <C>     <C>      <C>       <C>
Assets..................  $98,018 $ 3,463   $ 4,411   $105,892
Revenues................   18,036  22,449       767     41,252
Operating income........    3,683     206       617      4,506
Capital expenditures,
 net....................   47,327       5       146     47,478
Depreciation, depletion
 & amortization.........    6,710       3       202      6,915
<CAPTION>
                           OIL &                     CONSOLIDATED
SEPTEMBER 30, 1993          GAS   TRADING  CORPORATE    TOTAL
- ------------------        ------- -------  --------- -----------
                                     (IN THOUSANDS)
<S>                       <C>     <C>      <C>       <C>
Assets..................  $61,712 $ 1,821   $29,895   $ 93,428
Revenues................   15,921  26,381       384     42,686
Operating income........    5,000     503       407      5,910
Capital expenditures,
 net....................    6,008     --        (99)     5,909
Depreciation, depletion
 & amortization.........    5,913       2       215      6,130
<CAPTION>
                           OIL &                     CONSOLIDATED
SEPTEMBER 30, 1992          GAS   TRADING  CORPORATE    TOTAL
- ------------------        ------- -------  --------- -----------
                                     (IN THOUSANDS)
<S>                       <C>     <C>      <C>       <C>
Assets..................  $45,637 $ 3,990   $ 6,952   $ 56,579
Revenues................    6,922  16,726       637     24,285
Operating income (loss).      724    (412)      628        940
Capital expenditures,
 net....................    6,732      10       111      6,853
Depreciation, depletion
 & amortization.........    3,100       1       158      3,259
</TABLE>
 
  During the year ended September 30, 1994, one purchaser accounted for
$5,759,000 (14%) of the Company's total revenue. The purchaser accounted for
$1,046,000 (6%) of oil and gas segment revenues and $4,713,000 (21%) of trading
segment revenues.
 
  During the year ended September 30, 1993, two purchasers accounted for
$7,199,000 (17%) and $5,486,000 (13%) of the Company's total revenue. The first
purchaser accounted for $6,948,000 (44%) of oil and gas segment revenues and
$251,000 (1%) of trading segment revenues, and the second purchaser accounted
for $1,464,000 (9%) of oil and gas segment revenues and $4,022,000 (15%) of
trading segment revenues.
 
  During the year ended September 30, 1992, three purchasers accounted for
$3,316,000 (14%), $3,135,000 (13%), and $2,894,000, (12%), respectively, of the
Company's total revenue. The first purchaser accounted for $699,000 (10%) of
oil and gas segment revenues and $2,616,000 (16%) of trading segment revenues.
The second purchaser accounted for $53,000 (1%) and $3,082,000 (18%) of oil and
gas segment and trading segment revenues, respectively. The third purchaser
accounted for $2,894,000 (17%) of trading segment revenues.
 
                                      F-19
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
10. SUPPLEMENTAL CASH FLOW SCHEDULES AND INFORMATION
 
  Cash paid during years
<TABLE>
<CAPTION>
                                                                  1992 1993 1994
                                                                  ---- ---- ----
                                                                  (IN THOUSANDS)
<S>                                                               <C>  <C>  <C>
Income tax....................................................... $15  $75  $131
Interest.........................................................   6   13     5
</TABLE>
 
  During 1994 and 1993, increases in accounts payable of approximately
$8,059,000 and $1,704,000, respectively, related to the acquisition of property
and equipment. For 1992, decreases in accounts payable of approximately
$1,888,000 related to the acquisition of property and equipment.
 
11. RELATED PARTIES
 
  During the years ended September 30, 1994, 1993 and 1992 Zenith Drilling
Corporation was billed by the Company as operator, $2,290,000, $1,976,000 and
$363,000, respectively, for Zenith's portion of lease operating expenses and
development costs in certain leases operated by the Company. Also as a result
of Zenith's working interest ownership, the Company distributed oil and gas
revenue of $941,000, $1,128,000 and $856,000 to Zenith during 1994, 1993 and
1992, respectively. Zenith owns its working interests subject to the same terms
and arrangements that exist for all working interest owners in the properties.
Zenith Drilling Corporation owns 5.2 percent of the Company's common stock and
its president is a member of the Company's board of directors.
 
  During 1993, the Company and Zenith both sold their respective interests in
the Wattenberg Field. The Company and Zenith jointly negotiated the sale but
the purchaser independently determined the individual offer prices and entered
into separate sales agreements with each party.
 
  Grand Valley Corporation owns approximately 10 percent of a pipeline joint
venture for gas gathering of which a subsidiary of the Company owns
approximately 29 percent. A member of the Company's board of directors owns 10
percent of the outstanding stock, and is the president of Grand Valley
Corporation. His three adult children own the remaining 90 percent of the
outstanding stock of Grand Valley Corporation.
 
12. QUARTERLY INFORMATION (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                       THREE MONTHS ENDED
                                                --------------------------------
                                                12/31/93 3/31/94 6/30/94 9/30/94
                                                -------- ------- ------- -------
                                                (IN THOUSANDS, EXCEPT PER SHARE
                                                             DATA)
<S>                                             <C>      <C>     <C>     <C>
1994
  Net revenues................................. $ 9,584  $ 9,367 $9,715  $11,606
  Gross margin.................................   2,263    2,706  1,752    1,924
  Income from operations.......................   1,138    1,721    871      776
  Net income...................................   1,115    1,687    799      838
  Net income per share.........................     .09      .14    .07      .07
<CAPTION>
                                                       THREE MONTHS ENDED
                                                --------------------------------
                                                12/31/92 3/31/93 6/30/93 9/30/93
                                                -------- ------- ------- -------
                                                (IN THOUSANDS, EXCEPT PER SHARE
                                                             DATA)
<S>                                             <C>      <C>     <C>     <C>
1993
  Net revenues................................. $11,386  $13,043 $9,670  $ 7,505
  Gross margin.................................   2,301    4,037  4,334    2,864
  Income from operations.......................     621    2,111  1,682    1,496
  Net income...................................   1,333    1,393  1,108    1,922
  Net income per share.........................     .14      .14    .09      .16
</TABLE>
 
                                      F-20
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONCLUDED)
 
<TABLE>
<CAPTION>
                                                      THREE MONTHS ENDED
                                               --------------------------------
                                               12/31/91 3/31/92 6/30/92 9/30/92
                                               -------- ------- ------- -------
                                               (IN THOUSANDS, EXCEPT PER SHARE
                                                            DATA)
<S>                                            <C>      <C>     <C>     <C>
1992
  Net revenues................................  $5,699  $7,318  $4,650  $5,964
  Gross margin................................   1,305   1,793   1,391   1,144
  Income (loss) from operations...............     445     668     234    (407)
  Income before cumulative effect of change in
  method of
   accounting for income taxes................     400     601     211    (290)
  Net income (loss)...........................     983     601     211    (290)
  Earnings (loss) per share:
    From continuing operations................     .04     .06     .02    (.03)
    Net income (loss).........................     .10     .06     .02    (.03)
</TABLE>
 
  During the fourth quarter of 1993, the Company performed its annual review of
the differences between estimated taxable income and book income before taxes.
As a result of this review, the Company reversed $1,259,000 of the deferred tax
asset valuation allowance in the fourth quarter of fiscal 1993. In the first
quarter of fiscal 1993, $924,000 of the valuation allowance was reversed. These
amounts were recorded throughout the year during fiscal 1994. The valuation
allowance was reduced to reflect increases in oil and gas reserves that should
generate future taxable income.
 
  Income from operations for the fourth quarter of 1993 includes a gain of
$423,000 due to the favorable resolution of a disputed claim against the
Company.
 
                      SUPPLEMENTAL OIL AND GAS INFORMATION
 
  The following is information pertaining to the Company's oil and gas
producing activities for the years ended September 30, 1992, 1993 and 1994.
 
  Costs incurred in oil and gas property acquisition, exploration, and
development activities:
 
<TABLE>
<CAPTION>
                           1992    1993     1994
                          ------  -------  -------
                              (IN THOUSANDS)
<S>                       <C>     <C>      <C>
Acquisition of evaluated
properties..............  $  155  $   864  $13,832
Acquisition of
unevaluated properties..   1,418    1,013    8,446
Exploration costs.......   4,806   11,680   16,930
Development costs.......   3,086    7,464    5,234
Other, principally
proceeds from mineral
conveyances.............    (773) (15,397)    (173)
                          ------  -------  -------
Total additions to oil
and gas properties......  $8,692  $ 5,624  $44,269
                          ======  =======  =======
</TABLE>
 
  Results of operations from producing activities:
<TABLE>
<CAPTION>
                                                   1992    1993     1994
                                                  ------  -------  -------
                                                        (IN THOUSANDS)
<S>                                               <C>     <C>      <C>      <C>
Revenues......................................... $6,626  $14,976  $17,577
Production costs................................. (1,397)  (2,725)  (3,535)
Depreciation, depletion and amortization......... (3,100)  (5,913)  (6,710)
                                                  ------  -------  -------
                                                   2,129    6,338    7,332
Income tax expense...............................     41      165      110
                                                  ------  -------  -------
Results of operations from producing activities
 (excluding corporate overhead and interest
 cost)........................................... $2,088  $ 6,173  $ 7,222
                                                  ======  =======  =======
</TABLE>
 
 
                                      F-21
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
               SUPPLEMENTAL OIL AND GAS INFORMATION--(CONTINUED)
  Income tax expense for the years ended September 30, 1994, 1993 and 1992 are
different from the amount computed using the statutory tax rate due to tax net
operating loss, percentage depletion, and investment tax credit carryforwards.
 
 Oil and gas reserve information (unaudited):
 
  The following reserve related information for 1994, 1993 and 1992 is based on
estimates prepared by the Company and reviewed by Ryder Scott Company, an
independent reservoir engineer. Reserve estimates are inherently imprecise and
are continually subject to revisions based on production history, results of
additional exploration and development, prices of oil and gas and other
factors. All of the Company's oil and gas reserves are located in the United
States.
 
<TABLE>
<CAPTION>
                                 1992                  1993                  1994
                         --------------------- --------------------- ---------------------
                         OIL (MBBL) GAS (MMCF) OIL (MBBL) GAS (MMCF) OIL (MBBL) GAS (MMCF)
                         ---------- ---------- ---------- ---------- ---------- ----------
                                                  (IN THOUSANDS)
<S>                      <C>        <C>        <C>        <C>        <C>        <C>
Proved developed and
 undeveloped reserves:
Beginning of year.......    445       44,358       440      49,263      271       62,470
Revisions of previous
 estimates..............    (33)        (633)       40      (2,255)     (57)      (2,244)
Purchase of minerals in
 place .................      2          674       --          993       73       22,704
Extensions and
discoveries.............     94        8,469       112      25,529      251       75,345
Production..............    (55)      (3,502)      (75)     (7,214)     (54)      (9,069)
Sale of minerals in
place...................    (13)        (103)     (246)     (3,846)     --           --
                            ---       ------      ----      ------      ---      -------
End of year.............    440       49,263       271      62,470      484      149,206
                            ===       ======      ====      ======      ===      =======
Proved developed
reserves:
Beginning of year.......    284       32,511       345      37,099      271       43,866
                            ===       ======      ====      ======      ===      =======
End of year.............    345       37,099       271      43,866      333       80,012
                            ===       ======      ====      ======      ===      =======
</TABLE>
 
  The following is the standardized measure of discounted future net cash flows
relating to proved oil and gas reserves in which the Company has an interest.
 
<TABLE>
<CAPTION>
                                                    1992      1993      1994
                                                  --------  --------  --------
                                                        (IN THOUSANDS)
<S>                                               <C>       <C>       <C>
Future cash inflows.............................. $ 99,999  $129,547  $237,134
Future production costs..........................  (21,585)  (27,049)  (51,606)
Future development costs.........................  (10,128)  (14,948)  (35,382)
Future income tax expenses.......................   (6,798)  (18,093)  (23,582)
                                                  --------  --------  --------
Future net cash flows............................   61,488    69,457   126,564
10% annual discount for estimated timing of cash
 flows...........................................  (28,589)  (31,187)  (54,996)
                                                  --------  --------  --------
Standardized measure of discounted future net
 cash flows...................................... $ 32,899  $ 38,270  $ 71,568
                                                  ========  ========  ========
</TABLE>
 
  The future income tax expenses have been computed considering the tax basis
of the oil and gas properties, and net operating and other loss carryforwards.
 
                                      F-22
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
               SUPPLEMENTAL OIL AND GAS INFORMATION--(CONCLUDED)
 
  The following are the principal sources of changes in the standardized
measure of discounted future net cash flows:
 
<TABLE>
<CAPTION>
                                                    1992      1993      1994
                                                   -------  --------  --------
                                                        (IN THOUSANDS)
<S>                                                <C>      <C>       <C>
Net change in sales price and production costs.... $ 5,992  $  3,178  $(12,164)
Changes in estimated future development costs.....      21    (2,457)   (1,336)
Sales and transfers of oil and gas produced, net
 of production costs..............................  (5,229)  (12,252)  (14,041)
Net change due to extensions and discoveries......   6,043    17,762    39,533
Net change due to purchases and sales of minerals
 in place.........................................     247    (4,918)   17,504
Net change due to revisions in quantities.........    (246)   (1,215)     (788)
Previously estimated development costs incurred
 during the period................................   3,086     7,463     5,234
Net change in income taxes........................  (3,327)   (6,331)   (3,366)
Accretion of discount.............................   2,938     2,886     5,577
Other, principally revisions in estimates of
 timing of production.............................  (2,478)    1,255    (2,855)
                                                   -------  --------  --------
Net changes.......................................   7,047     5,371    33,298
Balance, beginning of year........................  25,852    32,899    38,270
                                                   -------  --------  --------
Balance, end of year.............................. $32,899  $ 38,270  $ 71,568
                                                   =======  ========  ========
</TABLE>
 
                                      F-23
<PAGE>
 
                         REPORT OF ARTHUR ANDERSEN LLP
 
                         INDEPENDENT PUBLIC ACCOUNTANTS
 
  We have audited in accordance with generally accepted auditing standards, the
financial statements of Barrett Resources Corporation included in this
Registration Statement and have issued our report thereon dated December 8,
1994. Our audit was made for the purpose of forming an opinion on the basic
financial statements taken as a whole. The schedules listed in the index are
presented for purposes of complying with the Securities and Exchange Commission
rules and are not part of the basic financial statements. These schedules have
been subjected to the auditing procedures applied in the audit of the basic
financial statements and, in our opinion, fairly state in all material respects
the financial data required to be set forth therein in relation to the basic
financial statements taken as a whole.
 
                                          Arthur Andersen LLP
 
Denver, Colorado
December 8, 1994
 
                                      F-24
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                                  SCHEDULE II
                    AMOUNTS RECEIVABLE FROM RELATED PARTIES
 
<TABLE>
<CAPTION>
                                                                BALANCE AT END
                                               DEDUCTIONS          OF PERIOD
                                             ---------------    ---------------
                         BEGINNING            AMOUNTS                     NOT
NAME OF DEBTOR           OF PERIOD ADDITIONS COLLECTED OTHER    CURRENT CURRENT
- --------------           --------- --------- --------- -----    ------- -------
                                           (IN THOUSANDS)
<S>                      <C>       <C>       <C>       <C>      <C>     <C>
FOR THE YEAR ENDED
 SEPTEMBER 30, 1994:
  William J. Barrett....   $--       $--       $--     $--       $--     $--
FOR THE YEAR ENDED
 SEPTEMBER 30, 1993:
  William J. Barrett....    --        --        --      --        --      --
FOR THE YEAR ENDED
 SEPTEMBER 30, 1992:
  William J. Barrett....    175       --        --      175(1)    --      --
</TABLE>
- --------
(1) Amounts related to note receivable due January 31, 1992 secured by common
    stock. Interest accrued at 10%. In January 1992, the collateral shares were
    retired by the Company in full satisfaction of the loan.
 
                                      F-25
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                                   SCHEDULE V
 
                         PROPERTY, PLANT AND EQUIPMENT
 
<TABLE>
<CAPTION>
                                                            OTHER
                         BEGINNING ADDITIONS               CHANGES       BALANCE AT
      DESCRIPTION        OF PERIOD  AT COST  RETIREMENTS ADD (DEDUCT)   END OF PERIOD
      -----------        --------- --------- ----------- ------------   -------------
                                               (IN THOUSANDS)
<S>                      <C>       <C>       <C>         <C>            <C>
FOR THE YEAR ENDED
 SEPTEMBER 30, 1994:
  Oil and gas
   properties...........  $52,210   $44,442    $   --      $   (173)(1)    $96,479
  Gas gathering systems.    2,808     2,941        --           --           5,749
  Furniture, vehicles
   and equipment........    1,518       387       (119)         --           1,786
FOR THE YEAR ENDED
 SEPTEMBER 30, 1993:
  Oil and gas
   properties...........   46,585    21,022        --       (15,397)(1)     52,210
  Gas gathering systems.    2,699       109        --           --           2,808
  Furniture, vehicles
   and equipment........    1,343       259        (84)         --           1,518
FOR THE YEAR ENDED
 SEPTEMBER 30, 1992:
  Oil and gas
   properties...........   39,100     9,465     (1,207)        (773)(1)     46,585
  Gas gathering systems.    2,513       186        --           --           2,699
  Furniture, vehicles
   and equipment........    1,222       214        (93)         --           1,343
</TABLE>
- --------
(1) Proceeds from mineral conveyances.
 
                                      F-26
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                                  SCHEDULE VI
 
               ACCUMULATED DEPRECIATION, DEPLETION, AMORTIZATION
                AND IMPAIRMENT OF PROPERTY, PLANT AND EQUIPMENT
 
<TABLE>
<CAPTION>
                                   ADDITIONS
                                   CHARGED TO
                         BEGINNING COSTS AND              OTHER CHANGES  BALANCE AT
      DESCRIPTION        OF PERIOD  EXPENSES  RETIREMENTS ADD (DEDUCT)  END OF PERIOD
      -----------        --------- ---------- ----------- ------------- -------------
                                                (IN THOUSANDS)
<S>                      <C>       <C>        <C>         <C>           <C>
FOR THE YEAR ENDED
 SEPTEMBER 30, 1994:
  Oil and gas
  properties............  $18,574    $6,515     $   --        $--          $25,089
  Gas gathering systems.      849       195         --         --            1,044
  Furniture, vehicles
   and equipment........      846       181         (71)       --              956
FOR THE YEAR ENDED
 SEPTEMBER 30, 1993:
  Oil and gas
   properties...........   12,840     5,734         --         --           18,574
  Gas gathering systems.      682       179         (12)       --              849
  Furniture, vehicles
   and equipment........      745       153         (52)       --              846
FOR THE YEAR ENDED
 SEPTEMBER 30, 1992:
  Oil and gas
   properties...........   11,132     2,915      (1,207)       --           12,840
  Gas gathering systems.      497       185         --         --              682
  Furniture, vehicles
   and equipment........      662       159         (76)       --              745
</TABLE>
 
                                      F-27
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                                 SCHEDULE VIII
 
                 VALUATION AND QUALIFYING ACCOUNTS AND RESERVES
 
<TABLE>
<CAPTION>
                                         ADDITIONS
                                   ---------------------
                                   CHARGED TO CHARGED TO
                         BEGINNING COSTS AND    OTHER    OTHER CHANGES  BALANCE AT
      DESCRIPTION        OF PERIOD  EXPENSES   ACCOUNTS  ADD (DEDUCT)  END OF PERIOD
      -----------        --------- ---------- ---------- ------------- -------------
                                               (IN THOUSANDS)
<S>                      <C>       <C>        <C>        <C>           <C>
FOR THE YEAR ENDED
 SEPTEMBER 30, 1994:
  Accounts receivable...  $   44    $   --      $  --        $  (1)       $   43
  Other assets (real
   estate held for
   investment)..........      10         --        --          (10)          --
  Deferred tax asset....   2,688     (1,537)       --          --          1,151
  Trading losses........    (100)       100        --          --            --
FOR THE YEAR ENDED
 SEPTEMBER 30, 1993:
  Accounts receivable...      74        --         --          (30)           44
  Other assets (real
   estate held for
   investment)..........      17        --         --           (7)           10
  Deferred tax asset....   4,871     (2,183)       --          --          2,688
  Trading losses........     268       (368)       --          --           (100)
FOR THE YEAR ENDED
 SEPTEMBER 30, 1992:
  Accounts receivable...      97        --         --          (23)           74
  Other assets (real
   estate held for
   investment)..........      77        --         --          (60)           17
  Deferred tax asset....     --         --       4,871         --          4,871
  Trading losses........     --         268        --          --            268
</TABLE>
 
                                      F-28
<PAGE>
 
                         BARRETT RESOURCES CORPORATION
 
                                   SCHEDULE X
 
                   SUPPLEMENTAL INCOME STATEMENT INFORMATION
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                CHARGES TO COSTS
                             ITEM                                 AND EXPENSES
                             ----                               ----------------
<S>                                                             <C>
FOR THE YEAR ENDED SEPTEMBER 30, 1994:
  Taxes, other than payroll and income taxes:
    Taxes on oil and gas production............................     $ 1,326
FOR THE YEAR ENDED SEPTEMBER 30, 1993:
  Taxes, other than payroll and income taxes:
    Taxes on oil and gas production............................       1,233
FOR THE YEAR ENDED SEPTEMBER 30, 1992:
  Taxes, other than payroll and income taxes:
    Taxes on oil and gas production............................         461
</TABLE>
 
                                      F-29
<PAGE>
 
                        INDEX TO CONSOLIDATED FINANCIAL
                              STATEMENTS OF PLAINS
 
<TABLE>
<S>                                                                        <C>
Consolidated Balance Sheets at December 31, 1994 and March 31, 1995
 (Unaudited).............................................................. F-31
Consolidated Statements of Earnings for Three Months ended March 31, 1994
 and 1995 (Unaudited)..................................................... F-32
Consolidated Statements of Cash Flows for Three Months Ended March 31,
 1994 and 1995 (Unaudited)................................................ F-33
Notes to Consolidated Financial Statements (March 31, 1995) (Unaudited)... F-34
Report Of Independent Public Accountants.................................. F-37
Consolidated Balance Sheets at December 31, 1993 and 1994................. F-38
Consolidated Statements of Earnings for each of the three years in the
 period ended December 31, 1994........................................... F-39
Consolidated Statements of Stockholders' Equity for each of the three
 years in the period ended December 31, 1994.............................. F-40
Consolidated Statements of Cash Flows for each of the three years in the
 period ended December 31, 1994........................................... F-41
Notes to Consolidated Financial Statements................................ F-42
</TABLE>
 
                                      F-30
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                          CONSOLIDATED BALANCE SHEETS
 
                     (SUCCESSFUL EFFORTS ACCOUNTING METHOD)
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                       DECEMBER 31,  MARCH 31,
                                                           1994        1995
                        ASSETS                         ------------ -----------
                                                                    (UNAUDITED)
<S>                                                    <C>          <C>
Current Assets
  Cash and equivalents................................   $  2,331    $  2,001
  Accounts receivable.................................      7,057       6,266
  Inventory, at lower of average cost or market.......        643         647
  Prepaid expenses....................................        422         622
                                                         --------    --------
    Total current assets..............................     10,453       9,536
                                                         --------    --------
Property and Equipment
  Oil and gas properties..............................    221,337     224,829
  Undeveloped leases..................................      4,568       4,601
  Other equipment and assets..........................      8,627       8,832
  Accumulated depreciation, depletion and amortiza-
   tion...............................................    (88,041)    (92,733)
                                                         --------    --------
    Net property and equipment........................    146,491     145,529
                                                         --------    --------
                                                         $156,944    $155,065
                                                         ========    ========
<CAPTION>
         LIABILITIES AND STOCKHOLDERS' EQUITY
<S>                                                    <C>          <C>
Current Liabilities
  Accounts payable....................................   $  2,245    $  1,338
  Undistributed production receipts...................      2,025       1,052
  Accrued taxes.......................................      2,069       2,985
  Accrued lease costs.................................        994       1,118
  Other accruals......................................      1,199       1,102
                                                         --------    --------
    Total current liabilities.........................      8,532       7,595
                                                         --------    --------
Long-Term Debt........................................     37,000      34,500
                                                         --------    --------
Deferred Income Taxes.................................     10,012      10,692
                                                         --------    --------
Postretirement Benefits...............................        927         952
                                                         --------    --------
Other Long-Term Liabilities...........................      1,017       1,023
                                                         --------    --------
Commitments and contingencies (Note 6)................
Stockholders' Equity
  Common stock, $0.01 par value; 20 million shares
   authorized; 9,813,055 and 9,822,028 shares
   outstanding, respectively..........................         98          98
  Additional paid-in capital..........................     20,278      20,383
  Retained earnings...................................     79,713      80,364
  Treasury stock, at cost.............................       (633)       (542)
                                                         --------    --------
    Total stockholders' equity........................     99,456     100,303
                                                         --------    --------
                                                         $156,944    $155,065
                                                         ========    ========
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-31
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                      CONSOLIDATED STATEMENTS OF EARNINGS
                                  (UNAUDITED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                THREE MONTHS
                                                                    ENDED
                                                               ----------------
                                                                MARCH    MARCH
                                                                 31,      31,
                                                                1994     1995
                                                               -------  -------
<S>                                                            <C>      <C>
Revenues
 Gas sales.................................................... $12,783  $12,346
 Oil and condensate sales.....................................   3,393    6,288
                                                               -------  -------
                                                                16,176   18,634
                                                               -------  -------
Operating Expenses
 Production--
  Lease operations............................................   2,720    3,519
  Production and property taxes...............................   1,957    2,432
  Transportation and processing...............................     649      821
  Net profit payments.........................................   1,288      668
 General and administrative...................................   1,843    2,061
 Depreciation, depletion and amortization.....................   4,467    4,983
 Exploration..................................................     425    1,694
 Interest expense, net........................................     113      584
 Other income.................................................    (102)    (129)
                                                               -------  -------
                                                                13,360   16,633
                                                               -------  -------
Earnings Before Taxes.........................................   2,816    2,001
                                                               -------  -------
Provision For Income Taxes
  Current.....................................................     140       81
  Deferred....................................................     648      680
                                                               -------  -------
                                                                   788      761
                                                               -------  -------
Net earnings.................................................. $ 2,028  $ 1,240
                                                               =======  =======
Average Shares Outstanding....................................   9,800    9,822
                                                               =======  =======
Net earnings per share........................................ $   .21  $   .13
                                                               =======  =======
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-32
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                  (UNAUDITED)
 
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                                                THREE MONTHS
                                                                    ENDED
                                                                --------------
                                                                MARCH   MARCH
                                                                 31,     31,
                                                                 1994    1995
                                                                ------  ------
<S>                                                             <C>     <C>
Operating Activities
  Net earnings................................................. $2,028  $1,240
  Adjustments to reconcile earnings to cash provided by opera-
   tions:
    Depreciation, depletion and amortization...................  4,467   4,983
    Deferred income taxes......................................    648     680
    Exploration expense........................................    425   1,694
    Postretirement benefits....................................     25      25
  Changes in Components of Working Capital:
    Accounts receivable........................................    443     791
    Prepaid expenses...........................................    145    (201)
    Accounts payable...........................................   (664)   (907)
    Undistributed production receipts..........................   (694)   (973)
    Other liabilities..........................................    447     943
                                                                ------  ------
Cash provided by operating activities..........................  7,270   8,275
                                                                ------  ------
Investing Activities
  Capital expenditures
    Exploration and Production................................. (1,429) (5,225)
    Other......................................................   (718)   (116)
  Acquisition of oil and gas properties........................ (1,738)   (383)
  Proceeds from sale of properties.............................    519       5
                                                                ------  ------
Cash used in investing activities.............................. (3,366) (5,719)
                                                                ------  ------
Financing Activities
  Repayments of long-term debt................................. (3,000) (2,500)
  Dividends paid...............................................   (588)   (589)
  Exercised stock options......................................    --      100
  Treasury stock issued (purchased)............................     (1)     96
  Other........................................................    --        7
                                                                ------  ------
Cash used in financing activities.............................. (3,589) (2,886)
                                                                ------  ------
Increase (decrease) in cash and equivalents....................    315    (330)
Cash and equivalents at beginning of period....................  2,660   2,331
                                                                ------  ------
Cash and equivalents at end of period.......................... $2,975  $2,001
                                                                ======  ======
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-33
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                 MARCH 31, 1995
                                   UNAUDITED
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
  The consolidated financial statements include the accounts of Plains
Petroleum Company and its wholly-owned subsidiaries, which are hereinafter
referred to collectively in these Notes to Consolidated Financial Statements as
the "Company". All significant intercompany transactions have been eliminated
in consolidation. Certain reclassifications have been made to 1994 amounts to
conform to the 1995 presentation. The unaudited March 31, 1995 and 1994
financial statements contain all adjustments (including normal recurring
accruals) which, in the opinion of management, are necessary for a fair
presentation of the results for the interim periods.
 
  The Company considers all short-term, highly liquid investments with a
maturity of three months or less to be cash equivalents. During the first
quarter ended March 31, 1995 and 1994, cash payments made for interest were
$579,000 and $225,000, respectively, and no cash payments were made for income
taxes in either quarter. The Company has not held during the first quarter, or
in any previous periods, any accounts which included derivative securities.
 
  The Company follows the successful efforts method of accounting for its oil
and gas exploration and development activities. Gains or losses from disposal
of properties are recognized currently. Reference should be made to the
Company's 1994 Form 10-K for additional information concerning all other
significant accounting policies, operations and financial condition.
 
2. LONG-TERM DEBT
 
  On February 17, 1995, a new credit agreement was entered into which replaced
the previous $60 million unsecured, revolving line of credit with a $150
million bank line. The new bank line has an initial borrowing base limitation
of $110 million, which is to be redetermined annually. Under the new agreement,
outstanding borrowings at the end of the revolving period in January 1997
convert to a six-year term loan. The new agreement also permits the Company to
repurchase its stock in an amount not to exceed $75 million during the
eighteen-month period following the effective date. Subsequent to that period,
aggregate treasury stock purchases and cash dividends for any four fiscal
quarters may not exceed 50% of net earnings for the preceding two years.
 
  The Company is required to pay only interest during the revolving period;
thereafter, principal is to be repaid over six years in equal quarterly
installments beginning in April 1997. Interest accrues, at the Company's
option, at rates equal to the agent bank's prime rate, the domestic certificate
of deposit rate or the London interbank eurodollar rate (LIBOR), in each case
plus a spread ranging from five-eighths of one percent (.625%) to two percent
(2.0%) per annum, depending on the amount of treasury stock the Company has
purchased and the level of the Company's borrowings relative to its borrowing
base. LIBOR was elected for the entire $34 1/2 million outstanding balance at
quarterend at an effective rate of 6.90% per annum.
 
  In April, 1995, the Company repaid $1 1/2 million under the credit agreement,
reducing the outstanding principal balance of loans to $33 million.
 
3. INCOME TAXES
 
  Statement of Financial Accounting Standards No. 109 provides that a deferred
tax liability or asset is determined based on the timing differences between
the bases used for financial versus tax reporting of assets and liabilities as
measured by the effective tax rates. For the quarter ended March 31, 1995, the
income tax
 
                                      F-34
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
expense equals the amounts computed by applying the statutory Federal and state
income tax rates, totaling 38%.
 
  For the prior year's first quarter, the income tax expense differs from the
amounts computed by applying the statutory rates to earnings before income
taxes. The reasons for these differences are shown as a percent of earnings as
follows:
 
<TABLE>
   <S>                                                                       <C>
   Statutory income tax rate................................................  34%
   State income tax rate....................................................   3
   Change in valuation allowance............................................  (7)
   Other items..............................................................  (2)
                                                                             ---
   Effective tax rate.......................................................  28%
                                                                             ===
</TABLE>
 
4. COMMITMENTS AND CONTINGENCIES
 
  On October 20, 1994, the Company issued a press release stating that it had
authorized its financial advisors to help the Company study strategic
alternatives in light of a recent Schedule 13-D filing by Cross Timbers Oil
Company. The press release stated that, as part of the study, the financial
advisors would seek indications of interest from certain possible merger
partners. The press release also indicated that the Company's board had amended
its shareholder rights plan.
 
  On November 2, 1994, a putative class action was filed in Delaware Chancery
Court. In that case, entitled Miller v. Cody, et al., the plaintiff has alleged
that certain named directors and the Company have, among other things, breached
their fiduciary duties by unreasonably amending the Company's shareholder
rights plan and otherwise acting to entrench themselves in office. Plaintiff
seeks various forms of injunctive relief, damages and an award of plaintiff's
costs and disbursements.
 
  The Company and the named directors deny the allegations of wrongdoing in the
complaint and intend to pursue a vigorous defense. A putative class action
entitled Behrens v. Miller, et al., that was filed on October 21, 1994, was
voluntarily dismissed without prejudice by the plaintiff. The allegations and
relief sought in the Behrens case were similar to those in the Miller action,
described above.
 
  On May 3, 1995, the Company announced it had executed a definitive merger
agreement with Barrett Resources Corporation (Barrett) and a subsidiary
thereof. Also on May 3, 1995, a putative class action, entitled Crandon Capital
Partners v. James A. Miller, et al., was filed in Delaware Chancery Court
against the Company and the members of its Board of Directors. In this suit it
is alleged that, among other things, the consideration to be paid the Company's
shareholders pursuant to such merger agreement is inadequate and "substantially
below the fair or inherent value of the Company." Plaintiff seeks various forms
of declaratory and injunctive relief, damages and an award of plaintiff's costs
and disbursements. The Company and the directors deny the allegations of
wrongdoing in the complaint and intend to pursue a vigorous defense.
 
  In addition, at March 31, 1995, the Company was party to certain other legal
proceedings which have arisen out of the ordinary course of business. Based on
the facts currently available, in management's opinion the liability,
individually or in the aggregate, if any, to the Company resulting from the
other actions will not have a material adverse effect on the Company's
consolidated financial position and results of operations.
 
 Environmental Controls
 
  Currently, there are no known environmental or other regulatory matters
related to the Company's operations which are reasonably expected to result in
a material liability to the Company. Compliance with
 
                                      F-35
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
environmental laws and regulations has not had, and is not expected to have, a
material adverse effect on the Company's capital expenditures, earnings or
competitive position.
 
5. SUBSEQUENT EVENT
 
  On May 2, 1995, Barrett, a subsidiary thereof and the Company executed a
definitive merger agreement pursuant to which the Company will merge with a
subsidiary of Barrett and, thereby, become a wholly-owned subsidiary of
Barrett. The terms of the merger agreement provide that each outstanding share
of the Company's common stock will be converted into the right to receive 1.3
shares of Barrett common stock.
 
  The merger will take the form of a tax-free exchange and will be accounted
for as a pooling of interests. The merger has been approved by the Boards of
Directors of Barrett and the Company and is subject to approval by their
respective stockholders as well as other customary conditions and approvals. At
the conclusion of the merger, Barrett will expand its Board of Directors to
include four members of the Company's Board.
 
                                      F-36
<PAGE>
 
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
To the Board of Directors and Stockholders of Plains Petroleum Company:
 
  We have audited the accompanying consolidated balance sheets of Plains
Petroleum Company (a Delaware corporation) and subsidiaries as of December 31,
1994 and 1993, and the related consolidated statements of earnings,
stockholders' equity and cash flows for each of the three years in the period
ended December 31, 1994. These financial statements are the responsibility of
the Company's management. Our responsibility is to express an opinion on these
financial statements based on our audits.
 
  We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of
material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant
estimates made by management, as well as evaluating the overall financial
statement presentation. We believe that our audits provide a reasonable basis
for our opinion.
 
  In our opinion, the consolidated financial statements referred to above
present fairly, in all material respects, the financial position of Plains
Petroleum Company and subsidiaries as of December 31, 1994 and 1993, and the
results of their operations and their cash flows for each of the three years in
the period ended December 31, 1994, in conformity with generally accepted
accounting principles.
 
                                          Arthur Andersen LLP
 
Denver, Colorado
January 31, 1995
 
                                      F-37
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                          CONSOLIDATED BALANCE SHEETS
 
                           DECEMBER 31, 1993 AND 1994
 
                     (SUCCESSFUL EFFORTS ACCOUNTING METHOD)
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                          ASSETS
                                                              1993      1994
                                                            --------  --------
<S>                                                         <C>       <C>
Current Assets
  Cash and equivalents..................................... $  2,660  $  2,331
  Accounts receivable......................................    5,422     7,057
  Inventory, at lower of average cost or market............      629       643
  Prepaid expenses.........................................      614       422
                                                            --------  --------
    Total current assets...................................    9,325    10,453
                                                            --------  --------
Property and Equipment (Note One)
  Oil and gas properties...................................  180,923   221,337
  Undeveloped leases.......................................    2,350     4,568
  Other equipment and assets...............................    7,883     8,627
  Accumulated depreciation, depletion and amortization.....  (73,689)  (88,041)
                                                            --------  --------
    Net property and equipment.............................  117,467   146,491
                                                            --------  --------
                                                            $126,792  $156,944
                                                            ========  ========
<CAPTION>
            LIABILITIES AND STOCKHOLDERS' EQUITY
<S>                                                         <C>       <C>
Current Liabilities
  Accounts payable......................................... $    958  $  2,245
  Undistributed production receipts........................    2,006     2,025
  Accrued taxes............................................    1,841     2,069
  Accrued lease costs......................................      780       994
  Other accruals...........................................    2,795     1,199
                                                            --------  --------
    Total current liabilities..............................    8,380     8,532
                                                            --------  --------
Long-Term Debt (Note Three)................................   13,500    37,000
                                                            --------  --------
Deferred Income Taxes (Notes One and Four).................    7,728    10,012
                                                            --------  --------
Postretirement benefits (Note Five)........................      860       927
                                                            --------  --------
Other long-term liabilities (Notes One and Five)...........    1,521     1,017
                                                            --------  --------
Commitments and Contingencies (Note Six)...................
Stockholders' Equity (Note One)
  Common stock, $0.01 par value; 20 million shares
   authorized; 9,800,618 and 9,813,055 shares outstanding,
   respectively............................................       98        98
  Additional paid-in capital...............................   19,498    20,278
  Retained earnings........................................   75,417    79,713
  Treasury stock, at cost..................................     (210)     (633)
                                                            --------  --------
    Total stockholders' equity.............................   94,803    99,456
                                                            --------  --------
                                                            $126,792  $156,944
                                                            ========  ========
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-38
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                      CONSOLIDATED STATEMENTS OF EARNINGS
 
                  YEARS ENDED DECEMBER 31, 1992, 1993 AND 1994
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                              1992     1993     1994
                             -------  -------  -------
<S>                          <C>      <C>      <C>
Revenues
  Gas sales................. $39,623  $46,189  $44,505
  Oil and condensate sales..  18,918   18,091   17,188
                             -------  -------  -------
                              58,541   64,280   61,693
                             -------  -------  -------
Operating Expenses
  Production--
    Lease operations........  11,503   12,537   10,810
    Production and property
     taxes..................   7,514    7,406    8,161
    Transportation and
     processing.............   1,875    2,640    2,476
    Net profit payments.....   4,575    4,748    3,247
  General and administra-
   tive.....................   5,559    6,415    7,350
  Depreciation, depletion
   and amortization.........  11,415   15,282   17,353
  Exploration...............   4,865    4,623    2,861
  Interest expense, net.....     690      643      762
  Other (income) expense....    (203)     219     (563)
  Property impairment.......     --     9,300      --
                             -------  -------  -------
                              47,793   63,813   52,457
                             -------  -------  -------
Earnings Before Taxes.......  10,748      467    9,236
                             -------  -------  -------
Provisions for Income Taxes
 (Note Four)
  Current...................     625      425      302
  Deferred..................     989     (341)   2,284
                             -------  -------  -------
                               1,614       84    2,586
                             -------  -------  -------
Net Earnings
  Before accounting changes.   9,134      383    6,650
  Accounting changes:
    Deferred income taxes
     (Note One).............     --     2,000      --
    Postretirement benefits,
     net of tax (Note Five).     --      (656)     --
                             -------  -------  -------
                             $ 9,134  $ 1,727  $ 6,650
                             =======  =======  =======
Average Shares Outstanding
 (Note One).................   9,796    9,797    9,808
                             =======  =======  =======
Earnings Per Share (Note
 One)
  Before accounting changes. $   .93  $   .04  $   .68
  Accounting changes:
    Deferred income taxes...     --       .20      --
    Postretirement benefits.     --      (.06)     --
                             -------  -------  -------
  Net earnings.............. $   .93  $   .18  $   .68
                             =======  =======  =======
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-39
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
 
                  YEARS ENDED DECEMBER 31, 1992, 1993 AND 1994
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                         COMMON STOCK                       TREASURY STOCK
                         -------------                      ------------------
                                       ADDITIONAL                                    TOTAL
                                        PAID-IN   RETAINED                       STOCKHOLDERS'
                         SHARES AMOUNT  CAPITAL   EARNINGS  SHARES    AMOUNT        EQUITY
                         ------ ------ ---------- --------  -------   --------   -------------
<S>                      <C>    <C>    <C>        <C>       <C>       <C>        <C>
Balance, December 31,
 1991................... 9,793   $98    $19,178   $69,258        (1)  $    (19)     $88,515
  Net earnings..........   --    --         --      9,134        --        --         9,134
  Cash dividends........   --    --         --     (2,350)       --        --        (2,350)
  Exercised stock op-
   tions................     7   --         183       --         --        --           183
  Treasury stock pur-
   chased...............   --    --         --        --         (5)      (158)        (158)
  Treasury stock issued.   --    --         --        --          1         34           34
                         -----   ---    -------   -------    ------   --------      -------
Balance, December 31,
 1992................... 9,800    98     19,361    76,042        (5)      (143)      95,358
  Net earnings..........   --    --         --      1,727        --        --         1,727
  Cash dividends........   --    --         --     (2,352)       --        --        (2,352)
  Exercised stock op-
   tions................     8   --         151       --         --        --           151
  Treasury stock pur-
   chased...............   --    --         --        --         (9)      (263)        (263)
  Treasury stock issued.   --    --         (14)      --          7        196          182
                         -----   ---    -------   -------    ------   --------      -------
Balance, December 31,
 1993................... 9,808    98     19,498    75,417        (7)      (210)      94,803
  Net earnings..........   --    --         --      6,650        --        --         6,650
  Cash dividends........   --    --         --     (2,354)       --        --        (2,354)
  Exercised stock op-
   tions................     2   --          45       --         --        --            45
  Common stock issued...    32   --         750       --         --        --           750
  Treasury stock pur-
   chased...............   --    --         --        --        (34)      (740)        (740)
  Treasury stock issued.   --    --         (15)      --         12        317          302
                         -----   ---    -------   -------    ------   --------      -------
Balance, December 31,
 1994................... 9,842   $98    $20,278   $79,713       (29)  $   (633)     $99,456
                         =====   ===    =======   =======    ======   ========      =======
</TABLE>
 
 
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-40
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
 
                  YEARS ENDED DECEMBER 31, 1992, 1993 AND 1994
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                    1992      1993      1994
                                                  --------  --------  --------
<S>                                               <C>       <C>       <C>
Operating Activities
  Net earnings................................... $  9,134  $  1,727  $  6,650
  Adjustments to reconcile earnings to cash
   provided by operations:
    Depreciation, depletion and amortization.....   11,415    15,282    17,353
    Property impairment..........................      --      9,300       --
    Deferred income taxes........................      989    (2,485)    2,284
    Exploration expense..........................    4,865     4,623     2,861
    Postretirement benefits......................      --        800        67
  Changes in components of working capital:
    Accounts receivable..........................      100     1,591    (1,635)
    Prepaid expenses.............................      333       (95)      192
    Accounts payable.............................   (1,283)     (813)    1,287
    Undistributed production receipts............     (180)     (219)       19
    Other liabilities............................    2,126     1,721    (1,154)
                                                  --------  --------  --------
Cash provided by operating activities............   27,499    31,432    27,924
                                                  --------  --------  --------
Investing Activities
  Capital expenditures
    Exploration and production...................  (18,043)  (15,632)  (20,525)
    Other........................................     (601)   (3,713)   (1,748)
  Acquisition of oil and gas properties..........  (12,162)   (4,171)  (27,414)
  Proceeds from sale of properties...............      569       525       435
                                                  --------  --------  --------
Cash used in investing activities................  (30,237)  (22,991)  (49,252)
                                                  --------  --------  --------
Financing Activities
  Long-term borrowings...........................   11,000       --     28,000
  Repayments of long-term debt...................   (6,000)   (6,500)   (4,500)
  Dividends paid.................................   (2,350)   (2,352)   (2,354)
  Exercised stock options........................      183       151        45
  Treasury stock purchased.......................     (124)      (81)     (438)
  Other..........................................        6       868       246
                                                  --------  --------  --------
Cash provided by (used in) financing activities..    2,715    (7,914)   20,999
                                                  --------  --------  --------
(Decrease) increase in cash and equivalents......      (23)      527      (329)
Cash and equivalents at beginning of year........    2,156     2,133     2,660
                                                  --------  --------  --------
Cash and equivalents at end of year.............. $  2,133  $  2,660  $  2,331
                                                  ========  ========  ========
</TABLE>
 
   The accompanying notes are an integral part of these financial statements.
 
                                      F-41
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
 Principles of Consolidation
 
  The consolidated financial statements include the accounts of Plains
Petroleum Company (Plains) and its wholly-owned subsidiaries, which are
hereinafter referred to collectively as the "Company". All significant
intercompany transactions have been eliminated. Certain reclassifications have
been made to 1992 and 1993 amounts to conform to the 1994 presentation.
 
 Oil and Gas Properties
 
  The Company follows the successful efforts method of accounting for its oil
and gas exploration and development activities. Acquisition costs, successful
exploration costs and all development costs are capitalized. Unsuccessful
exploratory drilling costs, seismic costs, and lease impairments and rentals
are expensed. Generally, gains or losses from disposal of properties are
recognized currently. The estimated salvage value of a property on its sale,
disposal or abandonment generally approximates the estimated dismantlement,
site restoration and abandonment costs. As a result, the accrued liability for
any excess cost is not material and not separately disclosed in the financial
statements.
 
  For certain oil properties located in the Permian Basin in west Texas and
southeastern New Mexico, a property impairment reserve of $9.3 million was
recorded in 1993 to adjust the net book value to an approximate net realizable
market value.
 
 Depreciation, Depletion and Amortization
 
  The unit-of-production method is used for computing depreciation, depletion
and amortization for oil and gas properties. The Company accrues for estimated
dismantlement and abandonment costs as a part of the unit-of-production
amortization. The accrued costs are classified as a component of accumulated
depreciation, depletion and amortization of the oil and gas properties.
Depreciation and amortization of other assets are provided for using the
straight-line method.
 
 Income Taxes
 
  Effective January 1, 1993, the Company adopted Statement of Financial
Accounting Standards No. 109 (FAS 109), "Accounting for Income Taxes". FAS 109
utilizes the liability method, with deferred taxes determined on the basis of
estimated future tax effects of differences between the financial statement and
tax bases of assets and liabilities. A valuation allowance must be established
for a deferred tax asset if a tax benefit may not be realized from the asset.
In 1993, the Company recognized the one-time, cumulative benefit of the
accounting change on prior years of $2 million and established a valuation
allowance for its deferred tax assets (see Note Four).
 
 Stockholders' Equity
 
  Quarterly dividend payments charged to retained earnings were $2,354,000 in
1994, $2,352,000 in 1993 and $2,350,000 in 1992. During these three years, the
Company has repurchased a total of approximately 48,000 shares of its common
stock, primarily for use in its employee benefit plans.
 
  Plains has a rights plan designed to insure that stockholders receive full
value for their shares in the event of certain takeover attempts.
 
                                      F-42
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
 Earnings per Share
 
  Earnings per share are computed based on the weighted average number of
common shares outstanding during each year. There are no other securities or
common stock equivalents which have a dilutive effect on earnings per share.
 
 Consolidated Statements of Cash Flows
 
  The Company considers all highly liquid debt instruments purchased with an
original maturity of three months or less to be cash equivalents.
 
  Supplemental disclosures of cash flow information:
 
<TABLE>
<CAPTION>
                                                                 1992 1993 1994
                                                                 ---- ---- ----
                                                                  IN THOUSANDS
     <S>                                                         <C>  <C>  <C>
     Cash paid during the year for:
       Interest................................................. $652 $785 $624
       Income taxes............................................. $503 $351 $207
</TABLE>
 
  Supplemental information of noncash investing and financing activities:
 
    In May 1994, the Company completed the contingent provisions of the 1990
  McAdams, Roux and Associates, Inc. (MRA) Agreement and Plan of Merger, as
  it related to the right of the MRA shareholders to receive additional
  shares of the Company's common stock and cash ("Contingent Consideration").
  The Contingent Consideration was based on the determination that additional
  reserves were attributed to certain property interests owned by MRA prior
  to the merger. Under the Agreement, 31,873 additional shares of the
  Company's common stock valued at $750,000 were issued to MRA's shareholders
  to satisfy a portion of the Contingent Consideration. A cash payment of $1
  1/2 million was made to the MRA shareholders for the remainder of the
  obligation.
 
    At yearend 1993, prior to the Contingent Consideration payments in 1994,
  an estimated current liability of $1,850,000 was reflected on the balance
  sheet for the estimated cash payment, with the remainder of $650,000
  related to the common stock to be issued reflected as a long-term
  liability.
 
2. ACQUISITIONS
 
  The Company acquired interests in certain producing oil and gas properties
located in Colorado, Wyoming, Montana, North Dakota, Utah and Oklahoma totaling
approximately $27 million. Properties were acquired from Anadarko Petroleum
Corporation on November 1, 1994 for approximately $24 million. The acquisition
was financed with a portion of the Company's bank line of credit (see Note
Three) and is reflected on the balance sheet using the purchase method of
accounting.
 
  The accompanying Consolidated Statements of Earnings include the operations
of the acquired properties commencing with completion of the purchases in 1994.
The unaudited pro forma financial information which follows represents
condensed consolidated operating results as if the acquisitions had been
consummated as of January 1, 1993. Consequently, the unaudited pro forma
adjustments to historical information reflect the addition of the revenues and
direct operating expenses of the acquired properties for the respective periods
in addition to pro forma adjustments for depreciation, depletion and
amortization expense, interest expense, general and administrative expense and
related income tax effects. Earnings per share is based on the weighted average
number of common shares outstanding of Plains' stock during each year. The pro
forma financial information is provided for comparative purposes only and
should be read in conjunction with the historical consolidated financial
statements of the Company. The pro forma financial
 
                                      F-43
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
information presented is not necessarily indicative of the combined financial
results as they may be in the future, or might have been during the periods
presented had the acquisition been consummated at the beginning of 1993.
 
<TABLE>
<CAPTION>
                                  AS            PRO FORMA            PRO FORMA
                               REPORTED        ADJUSTMENTS         CONSOLIDATED
                              --------------  --------------      ---------------
                              IN THOUSANDS, EXCEPT PER SHARE (UNAUDITED)
     <S>                      <C>             <C>                 <C>
     For the year ended De-
      cember 31, 1993
       Revenues.............. $       64,280    $       9,298       $       73,578
       Net earnings..........          1,727            1,609                3,336
       Earnings per share....            .18              .16                  .34
     For the year ended De-
      cember 31, 1994
       Revenues.............. $       61,693    $       6,968(1)           $68,661
       Net earnings..........          6,650              817(1)             7,467
       Earnings per share....            .68              .08(1)               .76
</TABLE>
- --------
(1) Represents the portion of 1994 activities prior to closing date.
 
3. LONG-TERM DEBT
 
  On February 17, 1995 (effective date), a new credit agreement was entered
into which replaced the previous $60 million unsecured, revolving line of
credit with a $150 million bank line. The new bank line has an initial
borrowing base limitation of $110 million, which will be redetermined annually.
Under the new agreement, outstanding borrowings at the end of the revolving
period in January 1997 convert to a term loan. The new agreement also provides
for a maximum of treasury stock purchases, which are not to exceed $75 million
during the eighteen-month period following the effective date. Subsequent to
that period, aggregate treasury stock purchases during the previous four fiscal
quarters may not exceed 50% of net earnings based upon the preceding two years.
 
  Interest only payments are required during the revolving period; thereafter,
principal is to be repaid over six years in equal quarterly installments
beginning in April 1997. The outstanding principal balance shall bear interest
at the prime rate (8 1/2% per annum at yearend 1994) during the revolving
period. In addition, if the aggregate amount of treasury stock purchases is
greater than $50 million, and the principal outstanding is 80% or greater of
the borrowing base, then the interest rate margin is increased an additional
one-half of one percent per annum. The Company may also elect at any time to
borrow funds at more favorable rates offered by the interbank eurocurrency
market (LIBOR), which it utilizes frequently, or by domestic certificates of
deposit. LIBOR was elected for the entire outstanding debt balance at yearend
1994 at an effective rate of 6.76% per annum.
 
  The margin on fixed interest rates and the commitment fee rates vary
depending upon the percentage of the loan principal outstanding in relation to
the borrowing base as determined under the agreement. The rates are on a
sliding scale from five-eighths of one percent to one and one-half percent per
annum. The commitment fee is from one-quarter of one percent to seventeen-
fortieths of one percent per annum.
 
  The Company must also maintain a book net worth of at least $80 million and a
ratio of current assets to current liabilities of at least 1 to 1. In addition,
the Company may pay cash dividends as long as the aggregate payments during the
previous four fiscal quarters do not exceed 50% of its net earnings based upon
the preceding two years.
 
 
                                      F-44
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
4. INCOME TAXES
 
  The effective tax rate on income from operations before taxes and the
cumulative effect of changes in accounting methods is different from the
prevailing federal income tax rate as follows:
 
<TABLE>
<CAPTION>
                                                     YEAR ENDED DECEMBER 31,
                                                     -------------------------
                                                        1993          1994
                                                     -----------   -----------
     <S>                                             <C>           <C>
     Statutory income tax rate......................          34%           34%
     Tax rate effect (decrease) of:
       Changes in valuation allowance...............         (24)          (14)
       State income taxes...........................           4             4
       Alternative minimum tax......................           2             2
       Other items..................................           2             2
                                                     -----------   -----------
                                                              18%           28%
                                                     ===========           ===
</TABLE>
 
  For 1992, income tax expense differs from the amounts computed by applying
the statutory Federal income tax rate to earnings before income taxes. The
reasons for these differences are shown as a percent of earnings as follows:
 
<TABLE>
<CAPTION>
                                                                           1992
                                                                           ----
     <S>                                                                   <C>
     Statutory income tax rate............................................  34%
     Utilization of tax loss carryforward................................. (25)
     Alternative minimum tax..............................................   2
     Other items, net (includes state taxes)..............................   4
                                                                           ---
                                                                            15%
                                                                           ===
</TABLE>
 
  The tax effect of temporary differences giving rise to the Company's
consolidated deferred income tax asset (liability) at December 31, 1994, is as
follows:
 
<TABLE>
<CAPTION>
                                                                  (IN THOUSANDS)
                                                                  --------------
     <S>                                                          <C>
     Long-term deferred tax assets:
       Operating loss carryforwards..............................    $  9,173
       Depletion and other credit carryforwards..................       4,804
       Deferred postretirement benefits and other................         719
                                                                     --------
                                                                     $ 14,696
     Valuation allowance.........................................        (112)
                                                                     --------
     Subtotal....................................................    $ 14,584
     Long-term deferred tax liabilities:
       Depreciation, depletion and amortization..................     (24,596)
                                                                     --------
     Deferred income tax liability...............................    $(10,012)
                                                                     ========
</TABLE>
 
  The Company has established a valuation allowance to the extent that it may
not be able to utilize its deferred tax assets. As of December 31, 1994, the
Company's estimate of taxable income increased for future periods which
resulted in a decrease in the valuation allowance from the prior yearend.
 
  As of December 31, 1994, the Company had estimated alternative minimum tax
loss carryforwards totaling $12 million. Such carryforwards are subject to
separate return limitation year provisions and they
 
                                      F-45
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
expire, if not utilized, during the years 1998 through 2005. The Company has no
loss carryforwards for state income tax purposes. The Company also has
available depletion and other credit carryforwards which may be utilized upon
expiration of the loss carryforwards.
 
5. EMPLOYEE BENEFIT PLANS
 
  The Company has a qualified, defined benefit retirement plan covering
substantially all of its employees. The benefits are based on a specified level
of the employee's compensation during plan participation. The Company's funding
policy is to contribute annually an amount that provides not only for benefits
attributed to service to date, but also for benefits expected to be earned in
the future. Plan assets consist of U.S. Treasury obligations, corporate stocks
and bonds, insured annuity contracts, cash and cash equivalents and accrued
interest. Contributions by the Company were $312,000, $341,000 and $239,000 for
the 1994, 1993 and 1992 plan years, respectively.
 
  The following table sets forth the plan's funded status:
 
<TABLE>
<CAPTION>
                                                          DECEMBER 31,
                                                     -------------------------
                                                      1992     1993     1994
                                                     -------  -------  -------
                                                          IN THOUSANDS
<S>                                                  <C>      <C>      <C>
Actuarial present value of benefit obligations:
  Accumulated benefit obligation, including vested
   benefits of $818,000, $1,290,000 and $1,637,000,
   respectively..................................... $  (880) $(1,383) $(1,666)
                                                     =======  =======  =======
  Projected benefit obligation...................... $(2,099) $(2,321) $(2,396)
  Plan assets at fair value.........................   1,504    1,977    2,205
                                                     -------  -------  -------
  Projected benefit obligation in excess of plan as-
   sets.............................................    (595)    (344)    (191)
  Unrecognized net (gain) loss......................     285       16     (141)
  Prior service cost not yet recognized in net peri-
   odic pension costs...............................      70       64       93
  Unrecognized net obligation being recognized over
   11 1/2, 10 1/2 and 9 1/2 years, respectively.....     160      146      132
                                                     -------  -------  -------
  Accrued pension cost.............................. $   (80) $  (118) $  (107)
                                                     =======  =======  =======
Net pension cost included the following components:
  Service cost--benefits earned..................... $   273  $   346  $   290
  Interest cost on projected benefit obligation.....     128      150      157
  Actual loss (return) on plan assets...............    (130)    (145)      70
  Net amortization of unrecognized obligation and
   deferral.........................................      55       28     (216)
                                                     -------  -------  -------
  Net periodic pension cost......................... $   326  $   379  $   301
                                                     =======  =======  =======
</TABLE>
 
  The weighted average discount rate used in determining the actuarial present
value of the projected benefit obligation was 8%. The rate of increase used for
compensation levels was 5% in 1994 and 1993 and 6% in 1992. The expected long-
term rate of return on assets was 8 1/2%.
 
  The Company also contributes the lesser of 10% of its net earnings or 10% of
employee compensation to a profit sharing plan of the Company. For 1994, 1993,
and 1992, the Company contributed $334,000, $188,000 and $471,000,
respectively.
 
  During 1993 and 1992, employees were allowed to defer from 1% to 10% of their
salary under a 401(k) salary redirection plan. Effective January 1, 1994, three
changes were made to the 401(k) plan. First, employee
 
                                      F-46
<PAGE>
 
                           PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
deferrals are limited to 9% of current salary. Second, the Company began
matching deferrals with contributions equal to 50% of each deferral up to 6%
of current salary. Company contributions are invested in Company stock and are
subject to a vesting schedule. Third, the payroll-based employee stock
ownership plan (PAYSOP) was terminated and merged into the 401(k) plan. Prior
to its termination and merger with the 401(k) plan, PAYSOP contributions were
based upon 1/2 of 1% of compensation and amounted to $22,700 for 1993 and
$23,500 for 1992.
 
  Plains has established three incentive stock option plans for employees and
a non-qualified stock option plan for its non-employee directors. Stock
options are granted at not less than 100% of the market value of the stock on
the date of grant. Plains has reserved one million shares under the employee
plans and 50,000 shares under the non-employee directors' plan. Options
granted, exercised and outstanding are as follows:
 
<TABLE>
<CAPTION>
                                                       NUMBER OF  OPTION PRICE
                                                        SHARES      PER SHARE
                                                       --------- ---------------
   <S>                                                 <C>       <C>
   Outstanding at December 31, 1991...................  280,728
     Granted..........................................  100,848  $26.94 - $27.50
     Exercised or canceled............................  (27,300)  16.25 -  33.56
                                                        -------
   Outstanding at December 31, 1992...................  354,276
     Granted..........................................   14,755   27.25 -  28.94
     Exercised or canceled............................  (42,350)  16.25 -  33.69
                                                        -------
   Outstanding at December 31, 1993...................  326,681
     Granted..........................................  202,952   20.69 -  26.25
     Exercised or canceled............................  (12,605)  26.19 -  33.56
                                                        -------
   Outstanding at December 31, 1994...................  517,028   16.25 -  33.69
                                                        =======
</TABLE>
 
  The Company has established an executive deferred compensation plan and a
directors' deferred fee plan which permit the deferral of current salary or
directors' fees for the purpose of providing funds at retirement or death for
employees, directors and their beneficiaries. The total accrued liability
under these plans at December 31, 1994 and 1993 was $1,006,000 and $838,000,
respectively.
 
  The Company provides postretirement healthcare benefits to retiring
employees and their spouses and a salary continuation (death) benefit to
certain eligible retirees. These benefits are subject to a medical cost
escalation limit, deductibles, co-payments, lifetime limits and other
limitations. The Company reserves the right to change or terminate the
benefits at any time.
 
  Effective January 1, 1993, the Company adopted Statement No. 106 (FAS 106)
issued by the Financial Accounting Standards Board on accounting for
postretirement benefits other than pensions. This statement requires the
accrual of the cost of providing postretirement benefits over the active
service period of the employee. FAS 106 requires recognition of the Company's
accumulated postretirement benefit obligation for its healthcare plan and
salary continuation plan existing at the time of adoption, as well as
incremental expense recognition for changes in the obligation attributable to
each successive fiscal period. The Company elected to immediately recognize
the accumulated liability as of the effective date, totaling approximately
$800,000 (pretax). Prior to 1993, the Company recognized postretirement costs
in the year the benefits were paid.
 
                                     F-47
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
  As of yearend, the status of the obligation, after reflecting anticipated
changes in plan provisions, is as follows:
 
<TABLE>
<CAPTION>
                                                                DECEMBER 31,
                                                                --------------
                                                                 1993    1994
                                                                ------  ------
                                                                     (IN
                                                                 THOUSANDS)
     <S>                                                        <C>     <C>
     Accumulated postretirement benefit obligation:
       Active plan participants...............................  $ (492) $ (458)
       Retirees...............................................    (320)   (302)
                                                                ------  ------
                                                                  (812)   (760)
     Plan assets..............................................       0*      0*
                                                                ------  ------
     Net accumulated postretirement benefit obligation........    (812)   (760)
     Unrecognized net gain from past experience different from
      that assumed and from changes in assumptions............     (48)   (167)
                                                                ------  ------
     Accrued postretirement benefit cost......................  $ (860) $ (927)
                                                                ======  ======
</TABLE>
 
- --------
* The Company has specifically identified certain assets, primarily insurance
  policies owned by the Company, to fund postretirement benefit obligations.
  However, these assets are not considered "plan assets" as defined in the tax
  regulations. As of December 31, 1994 and 1993, the insurance policies have a
  total cash surrender value of approximately $860,000 and $770,000,
  respectively.
 
  Net periodic postretirement benefit cost included the following components:
 
<TABLE>
<CAPTION>
                                                                       1993 1994
                                                                       ---- ----
   <S>                                                                 <C>  <C>
   Service cost of benefits earned.................................... $ 36 $ 41
   Interest cost on accumulated postretirement benefit obligation.....   60   61
                                                                       ---- ----
   Net periodic postretirement benefit cost........................... $ 96 $102
                                                                       ==== ====
</TABLE>
 
  The Company has utilized independent actuaries to estimate the expected costs
of healthcare benefits using current data from the Company and various
assumptions. The estimates are subject to significant revisions based on a
number of factors, including possible changes in the assumed healthcare cost
trend rate and the discount rate used in the calculations.
 
  The accumulated postretirement benefit obligation was computed using an
assumed discount rate of 8%. The future healthcare cost trend rate was assumed
to be 11 1/2%, then it declines by 1.5 percentage points for each of three
successive years and remains constant at 7% thereafter. If the healthcare cost
trend rate was increased one percent for all future years, both the accumulated
postretirement benefit obligation and the aggregate of service and interest
costs for 1994 would have increased 1%.
 
6. COMMITMENTS AND CONTINGENCIES
 
  The Company leases office facilities in Lakewood, Colorado; Midland, Texas;
Lakin, Kansas and Gillette, Wyoming under operating leases with 6 to 60 months
remaining on the lease terms as of December 31, 1994. The Company's computer
and phone system leases terminate in 2 to 31 months. Minimum annual rental
commitments amount to approximately $725,514 in 1995, $370,215 in 1996,
$124,310 in 1997, $112,404 in 1998 and $3,800 in 1999.
 
  On October 20, 1994, the Company issued a press release stating that it had
authorized its financial advisors to help the Company study strategic
alternatives in light of a recent Schedule 13-D filing by Cross
 
                                      F-48
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
Timbers Oil Company. The press release stated that as part of the study, the
financial advisors would seek indications of interest from certain possible
merger partners. The press release also indicated that the Company's board had
amended its shareholder rights plan.
 
  On November 2, 1994, a putative class action was filed in Delaware Chancery
Court. In that case, entitled Miller v. Cody, et al., the plaintiff has alleged
that certain named directors and the Company have, among other things, breached
their fiduciary duties by unreasonably amending the Company's shareholder
rights plan and otherwise acting to entrench themselves in office. Plaintiff
seeks various forms of injunctive relief, damages and an award of plaintiff's
costs and disbursements.
 
  The Company and the named directors deny the allegations of wrongdoing in the
complaint and intend to pursue a vigorous defense. A putative class action
entitled Behrens v. Miller, et al., that was filed on October 21, 1994, was
voluntarily dismissed without prejudice by the plaintiff. The allegations and
relief sought in the Behrens case were similar to those in the Miller action,
described above.
 
  At December 31, 1994, the Company was a party to certain legal proceedings
which have arisen out of the ordinary course of business. Based on the facts
currently available, in management's opinion the liability, individually or in
the aggregate, if any, to the Company resulting from such actions will not have
a material adverse effect on the Company's consolidated financial position or
results of operations.
 
 Environmental Controls
 
  At yearend 1994, there were no known environmental or other regulatory
matters related to the Company's operations which are reasonably expected to
result in a material liability to the Company. Compliance with environmental
laws and regulations has not had, and is not expected to have, a material
adverse effect on the Company's capital expenditures, earnings or competitive
position.
 
7. COMPARATIVE QUARTERLY RESULTS (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                      1993
                                   ---------------------------------------------
                                     1ST     2ND     3RD     4TH     YEAR
                                   ------- ------- ------- -------  -------
                                                IN THOUSANDS
<S>                                <C>     <C>     <C>     <C>      <C>      <C>
Revenues.........................  $17,215 $16,487 $15,331 $15,247  $64,280
Direct operating expenses(a)(b)..   13,975  10,203  10,328  17,407   51,913
Other expenses...................    3,149   3,295   2,891   2,565   11,900
                                   ------- ------- ------- -------  -------
Earnings (loss) before taxes.....       91   2,989   2,112  (4,725)     467
Income tax provision (benefit)...       16     538     380    (850)      84
                                   ------- ------- ------- -------  -------
Earnings (loss) before accounting
 changes.........................       75   2,451   1,732  (3,875)     383
Cumulative effect on prior years
 of accounting changes...........    1,344     --      --      --     1,344
                                   ------- ------- ------- -------  -------
Net earnings (loss)..............  $ 1,419 $ 2,451 $ 1,732 $(3,875) $ 1,727
                                   ======= ======= ======= =======  =======
Earnings per share
  Earnings (loss) before
   accounting changes............  $   .01 $   .25 $   .18 $  (.39) $   .04*
  Accounting changes.............      .13     --      --      --       .14*
                                   ------- ------- ------- -------  -------
Net earnings (loss) per share....  $   .14 $   .25 $   .18 $  (.39) $   .18
                                   ======= ======= ======= =======  =======
</TABLE>
 
                                      F-49
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
<TABLE>
<CAPTION>
                                                        1994
                                       ---------------------------------------
                                         1ST     2ND     3RD     4TH    YEAR
                                       ------- ------- ------- ------- -------
                                                    IN THOUSANDS
<S>                                    <C>     <C>     <C>     <C>     <C>
Revenues.............................. $16,176 $14,705 $12,616 $18,196 $61,693
Direct operating expenses(a)..........  11,080   9,355   9,189  12,423  42,047
Other expenses........................   2,280   2,650   2,087   3,393  10,410
                                       ------- ------- ------- ------- -------
Earnings before taxes.................   2,816   2,700   1,340   2,380   9,236
Income tax provision..................     788     756     376     666   2,586
                                       ------- ------- ------- ------- -------
Net earnings.......................... $ 2,028 $ 1,944 $   964 $ 1,714 $ 6,650
                                       ======= ======= ======= ======= =======
Earnings per share.................... $   .21 $   .20 $   .10 $   .18 $   .68*
                                       ======= ======= ======= ======= =======
</TABLE>
- --------
 * Difference due to rounding.
(a) Direct operating expenses are those associated directly with oil and gas
    revenues and include lease operations, production and property taxes,
    transportation and processing, net profit payments, and depreciation,
    depletion and amortization. Gross profit would be computed as the excess of
    revenues over direct operating expenses.
(b) Also included in 1993 direct operating expenses is a $3.3 million charge in
    the first quarter and $6 million charge in the fourth quarter for property
    impairment.
 
8. OIL AND GAS PRODUCING ACTIVITIES (UNAUDITED)
 
  The following disclosures concerning the Company's oil and gas producing
activities are presented in accordance with FAS No. 69, "Disclosures about Oil
and Gas Producing Activities".
 
<TABLE>
<CAPTION>
                                                           DECEMBER 31
                                                    --------------------------
                                                      1992     1993     1994
                                                    -------- -------- --------
                                                           IN THOUSANDS
   <S>                                              <C>      <C>      <C>
   Capitalized Costs at Yearend
   Oil and gas properties--
     Producing..................................... $153,817 $166,626 $207,036
     Proved undeveloped............................   14,242   14,297   14,301
                                                    -------- -------- --------
                                                     168,059  180,923  221,337
     Undeveloped leases............................    2,252    2,350    4,568
                                                    -------- -------- --------
                                                     170,311  183,273  225,905
     Accumulated depreciation, depletion and
      amortization.................................   49,512   71,848   85,353
                                                    -------- -------- --------
       Net capitalized costs....................... $120,799 $111,425 $140,552
                                                    ======== ======== ========
   Costs Incurred During the Year (capitalized or
    expensed)--
     Acquisition of properties:
       proved...................................... $ 12,162 $  4,171 $ 25,808
       unproved....................................      --       --     1,606
     Exploration costs.............................    4,034    3,567    6,898
     Development costs.............................   12,360   14,074   14,956
                                                    -------- -------- --------
       Total costs incurred........................ $ 28,556 $ 21,812 $ 49,268
                                                    ======== ======== ========
</TABLE>
 
 
                                      F-50
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 Estimated Oil and Gas Reserve Quantities
 
  All of the Company's proved developed reserve quantities were estimated at
yearend 1994 by Netherland, Sewell & Associates, Inc., an independent petroleum
engineering firm. Proved undeveloped reserves were estimated by the Company's
petroleum engineers and amounted to approximately 11% of total proved reserve
equivalents at December 31, 1994. Proved developed reserve quantities in prior
years were also estimated annually by independent petroleum engineers.
 
  The reserve balances presented below are estimates of net quantities which
can be expected to be recovered commercially at current prices and with
existing conventional equipment and operating methods. Proved developed
reserves are only those reserves expected to be recovered from existing wells.
Proved undeveloped reserves, estimated to be 20.1 Bcf of gas and 3.5 million
barrels of oil at yearend 1994, include those reserves expected to be recovered
from new wells and improved recovery projects where additional expenditures are
required. The Company's reserves are in the lower 48 states, principally in the
Kansas and Oklahoma portions of the Hugoton Field, the Permian Basin of west
Texas and southeastern New Mexico, and in the Powder River and Green River
Basins of Wyoming.
 
<TABLE>
<CAPTION>
                                                                 GAS      OIL
                                                               (MMCF)   (MBBLS)
                                                               -------  -------
     <S>                                                       <C>      <C>
     Proved developed and undeveloped reserves--
     Balance, December 31, 1991............................... 338,309  11,122
       Extensions, discoveries and other additions............   1,993     171
       Acquisitions...........................................     769   2,193
       Production............................................. (21,654) (1,039)
       Revisions..............................................  (3,652) (2,406)
       Sales of reserves......................................    (177)    (36)
                                                               -------  ------
     Balance, December 31, 1992............................... 315,588  10,005
       Extensions, discoveries and other additions............   6,288   1,194
       Acquisitions...........................................   1,537     216
       Production............................................. (23,757) (1,220)
       Revisions..............................................     (38) (3,444)
       Sales of reserves......................................    (130)    (66)
                                                               -------  ------
     Balance, December 31, 1993............................... 299,488   6,685
       Extensions, discoveries and other additions............  19,639   2,297
       Acquisitions...........................................  20,277   2,461
       Production............................................. (23,925) (1,236)
       Revisions..............................................  (2,958)    828
       Sales of reserves......................................     (42)    (62)
                                                               -------  ------
     Balance, December 31, 1994............................... 312,479  10,973
                                                               =======  ======
       Proved Developed Reserves
       December 31, 1992...................................... 307,262   6,945
       December 31, 1993...................................... 293,814   5,286
       December 31, 1994...................................... 292,321   7,466
</TABLE>
 
                                      F-51
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
            STANDARDIZED MEASURE OF DISCOUNTED FUTURE NET CASH FLOWS
                 AND CHANGE THEREIN RELATING TO PROVED RESERVES
                                  (UNAUDITED)
 
<TABLE>
<CAPTION>
                                                         DECEMBER 31
                                                  ----------------------------
                                                    1992      1993      1994
                                                  --------  --------  --------
                                                         IN THOUSANDS
<S>                                               <C>       <C>       <C>
Future cash inflows.............................. $748,881  $654,658  $698,988
Future production costs.......................... (300,609) (238,715) (259,628)
Future development costs.........................  (13,135)   (8,316)  (16,624)
                                                  --------  --------  --------
Future net cash flows before taxes...............  435,137   407,627   422,736
10% annual discount factor....................... (208,407) (182,071) (187,735)
                                                  --------  --------  --------
Discounted future cash flows before taxes........  226,730   225,556   235,001
Discounted future income taxes...................  (63,484)  (63,156)  (70,500)
                                                  --------  --------  --------
Standardized measure of discounted future net
 cash flows...................................... $163,246  $162,400  $164,501
                                                  ========  ========  ========
<CAPTION>
                                                         DECEMBER 31
                                                  ----------------------------
                                                    1992      1993      1994
                                                  --------  --------  --------
                                                         IN THOUSANDS
<S>                                               <C>       <C>       <C>
Standardized measure--beginning of year.......... $169,629  $163,246  $162,400
Increases (Decreases):
  Purchase of reserves...........................   12,663       250    21,546
  Sales, net of production costs.................  (34,798)  (38,905)  (36,999)
  Net changes in future prices and production
   costs.........................................   (3,554)   11,309   (10,507)
  Extensions, discoveries and additions, less re-
   lated costs...................................    2,734     6,859    21,772
  Changes in future development costs............   13,275     4,868     3,506
  Revisions of previous quantity estimates.......  (10,835)  (13,501)    1,298
  Sale of reserves...............................     (150)     (521)     (246)
  Accretion of discount..........................   23,237    22,673    22,555
  Net change in income taxes.....................     (745)      328    (7,344)
  Changes in production rates related to timing
   of demand.....................................   (8,210)    5,794   (13,480)
                                                  --------  --------  --------
Standardized measure--end of year................ $163,246  $162,400  $164,501
                                                  ========  ========  ========
</TABLE>
 
  The 1994, 1993 and 1992 standardized measure of discounted future net cash
flows and related changes were computed using either yearend prices or prices
under contractual arrangements for oil and gas and yearend costs. A significant
portion of the Company's gas reserves are dedicated under a long-term contract
with its principal purchaser, K N Energy, Inc. (K N). The price applicable to
this contract is subject to annual renegotiation. Sales of gas to K N during
1994, 1993 and 1992 represented 34%, 48% and 47%, respectively, of total
revenues of the Company. During 1994 and 1993, Associated Natural Gas, Inc.
purchased natural gas representing 11% of total revenues. A second major
customer during 1992 was Scurlock Oil Company which purchased oil representing
13% of total revenues of the Company. There were no other sales to customers
which accounted for more than 10% of total revenues of the Company during the
three years presented.
 
  At December 31, 1994, the Company believes that there are no material
estimated future dismantlement and abandonment costs for its properties. For
the purpose of computing the discounted future net cash flows, estimated future
dismantlement and abandonment costs are assumed to equal the estimated salvage
values of the properties.
 
 
                                      F-52
<PAGE>
 
                            PLAINS PETROLEUM COMPANY
 
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
  The Company periodically performs an impairment test by comparing total
capitalized costs with future undiscounted net revenues of its properties on a
geographic basis, by field or basin. No impairment was recognized in 1994. An
impairment of $9.3 million was recorded in 1993.
 
  Effective tax rates of 30% for 1994 and 28% for 1993 and 1992 were used in
computing discounted future income taxes, respectively, which reflect the
benefits which will accrue to the Company because of the reduction from
statutory tax rates due to the utilization of available tax loss carryforwards
which are present at yearend (see Note Four). Accretion of discount recognizes
the increase resulting from the passage of time.
 
                                      F-53
<PAGE>
 
                                                                         ANNEX I
                                                                  CONFORMED COPY
 
 
                          AGREEMENT AND PLAN OF MERGER
 
                                     AMONG
 
                         BARRETT RESOURCES CORPORATION,
 
                              VANILLA CORPORATION*
 
                                      AND
 
                            PLAINS PETROLEUM COMPANY
 
                            DATED AS OF MAY 2, 1995
 
- --------
*Now known as Barrett Energy Inc.
<PAGE>
 
                               TABLE OF CONTENTS
 
                                                                   PAGE
                                                                   ----
 Parties and Recitals...........................................    I-5
 
                                   ARTICLE I
 
                                   The Merger
 
 Section 1.1  The Merger........................................    I-5
 Section 1.2  Effective Time....................................    I-5
 Section 1.3  Effects of the Merger.............................    I-6
 Section 1.4  Certificate of Incorporation, By-laws
              and Directors.....................................    I-6
 Section 1.5  Conversion of Securities..........................    I-6
 Section 1.6  Parent to Make Certificates Available.............    I-6
 Section 1.7  Dividends; Transfer Taxes.........................    I-7
 Section 1.8  No Fractional Securities..........................    I-7
 Section 1.9  Return of Exchange Fund...........................    I-8
 Section 1.10 Adjustment of Exchange Ratio......................    I-8
 Section 1.11 No Further Ownership Rights in Company Common
              Stock.............................................    I-8     
 Section 1.12 Closing of Company Transfer Books.................    I-8
 Section 1.13 Further Assurances................................    I-8
 Section 1.14 Closing...........................................    I-8
 
                                   ARTICLE II
 
                    Representations and Warranties of Parent
 
 Section 2.1  Organization, Standing and Power..................    I-9
 Section 2.2  Capital Structure.................................    I-9
 Section 2.3  Authority; Non-Contravention......................    I-9
 Section 2.4  SEC Documents.....................................   I-11
 Section 2.5  Engineering Reports...............................   I-11
 Section 2.6  Oil and Gas Reserve Information...................   I-11
 Section 2.7  Registration Statement and Proxy Statement........   I-12
 Section 2.8  Absence of Material Adverse Change................   I-12
 Section 2.9  Pooling of Interests; Reorganization..............   I-12
 Section 2.10 Taxes.............................................   I-13
 Section 2.11 Title to Property.................................   I-13
 Section 2.12 Employee Benefit Plans............................   I-13
 Section 2.13 Labor Matters.....................................   I-14
 Section 2.14 Environmental Matters.............................   I-14
 Section 2.15 Litigation........................................   I-15
 Section 2.16 Governmental Licenses and Permits; Compliance
              with Law..........................................   I-16
 Section 2.17 Required Vote of Parent Stockholders..............   I-16
 Section 2.18 Opinion of Financial Advisor......................   I-16
 Section 2.19 Brokers...........................................   I-16
 
                                  ARTICLE III
 
                 Representations and Warranties of the Company
 
 Section 3.1  Organization, Standing and Power..................   I-16
 Section 3.2  Capital Structure.................................   I-16
 Section 3.3  Authority; Non-Contravention......................   I-17
 
                                      I-2
<PAGE>
 
<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----
 <C>          <S>                                                           <C>
 Section 3.4  SEC Documents...............................................  I-18
 Section 3.5  Engineering Reports.........................................  I-18
 Section 3.6  Oil and Gas Reserve Information.............................  I-18
 Section 3.7  Registration Statement and Proxy Statement..................  I-19
 Section 3.8  Absence of Material Adverse Change..........................  I-19
 Section 3.9  Pooling of Interests; Reorganization........................  I-19
 Section 3.10 Taxes.......................................................  I-20
 Section 3.11 Title to Property...........................................  I-20
 Section 3.12 Employee Benefit Plans......................................  I-20
 Section 3.13 Labor Matters...............................................  I-21
 Section 3.14 Environmental Matters.......................................  I-21
 Section 3.15 Litigation..................................................  I-21
 Section 3.16 Governmental Licenses and Permits; Compliance with Law......  I-22
 Section 3.17 Required Vote of the Company Stockholders...................  I-22
 Section 3.18 Company Action..............................................  I-22
 Section 3.19 Section 203 of the DGCL Not Applicable......................  I-22
 Section 3.20 Amendment to Company Rights Agreement.......................  I-22
 Section 3.21 Opinion of Financial Advisor................................  I-23
 Section 3.22 Brokers.....................................................  I-23
 
                                   ARTICLE IV
 
                  Representations and Warranties Regarding SUB
 
 Section 4.1  Organization and Standing...................................  I-23
 Section 4.2  Capital Structure...........................................  I-23
 Section 4.3  Authority; Non-Contravention................................  I-23
 
                                   ARTICLE V
 
                   Covenants Relating to Conduct of Business
 
 Section 5.1  Conduct of Business Pending the Merger......................  I-24
 Section 5.2  No Solicitation.............................................  I-25
 Section 5.3  Pooling of Interests; Reorganization........................  I-26
 Section 5.4  Conduct of Business of Sub Pending the Merger...............  I-26
 
                                   ARTICLE VI
 
                             Additional Agreements
 
 Section 6.1  Stockholder Approval........................................  I-26
 Section 6.2  Registration Statement and Proxy Statement..................  I-27
 Section 6.3  Access to Information.......................................  I-27
 Section 6.4  Compliance with the Securities Act; Pooling.................  I-28
 Section 6.5  Stock Exchange Listing......................................  I-28
 Section 6.6  Fees and Expenses...........................................  I-28
 Section 6.7  Company Stock Options.......................................  I-29
 Section 6.8  Reasonable Efforts..........................................  I-30
 Section 6.9  Public Announcements........................................  I-30
 Section 6.10 Real Estate Transfer and Gains Tax..........................  I-30
</TABLE>
 
                                      I-3
<PAGE>
 
<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----
 <C>          <S>                                                           <C>
 Section 6.11 Indemnification; Directors and Officers Insurance..........   I-31
 Section 6.12 Employee Benefits..........................................   I-31
 Section 6.13 Stay Bonuses; Merit Bonuses; Severance Policy..............   I-31
 
                                  ARTICLE VII
 
                       Conditions Precedent to the Merger
 
 Section 7.1  Conditions to Each Party's Obligation to Effect the Merger.   I-33
 Section 7.2  Conditions to Obligation of the Company to Effect the
                Merger...................................................   I-33
 Section 7.3  Conditions to Obligations of Parent and Sub to Effect the
                Merger...................................................   I-36
 
                                  ARTICLE VIII
 
                       Termination, Amendment and Waiver
 
 Section 8.1  Termination................................................   I-38
 Section 8.2  Effect of Termination......................................   I-39
 Section 8.3  Amendment..................................................   I-39
 Section 8.4  Waiver.....................................................   I-40
 
                                   ARTICLE IX
 
                               General Provisions
 
 Section 9.1  Non-Survival of Representations and Warranties.............   I-40
 Section 9.2  Notices....................................................   I-40
 Section 9.3  Interpretation.............................................   I-41
 Section 9.4  Counterparts...............................................   I-41
 Section 9.5  Entire Agreement; No Third-Party Beneficiaries.............   I-41
 Section 9.6  Governing Law..............................................   I-41
 Section 9.7  Assignment.................................................   I-41
 Section 9.8  Severability...............................................   I-41
 Section 9.9  Enforcement of This Agreement..............................   I-42
 Section 9.10 Jurisdiction and Venue.....................................   I-42
</TABLE>
 
                                      I-4
<PAGE>
 
                          AGREEMENT AND PLAN OF MERGER
 
  AGREEMENT AND PLAN OF MERGER, dated as of May 2, 1995 (this "Agreement"),
among Barrett Resources Corporation, a Delaware corporation ("Parent"), Vanilla
Corporation,* a Delaware corporation and a wholly-owned subsidiary of Parent
("Sub"), and Plains Petroleum Company, a Delaware corporation (the "Company")
(Sub and the Company being hereinafter collectively referred to as the
"Constituent Corporations").
 
                                  WITNESSETH:
 
  WHEREAS, the respective Boards of Directors of Parent, Sub and the Company
have approved and declared fair to and advisable and in the best interests of
their respective stockholders the merger of Sub and the Company (the "Merger"),
upon the terms and subject to the conditions set forth herein, whereby each
issued and outstanding share of Common Stock, par value $.01 per share, of the
Company ("Company Common Stock") not owned directly or indirectly by Parent or
the Company, will be converted into shares of Common Stock, par value $.01 per
share, of Parent ("Parent Common Stock");
 
  WHEREAS, for federal income tax purposes, it is intended that the Merger
shall qualify as a reorganization within the meaning of Section 368(a) of the
Internal Revenue Code of 1986, as amended (the "Code");
 
  WHEREAS, it is intended that the Merger shall be recorded for accounting
purposes as a pooling of interests; and
 
  WHEREAS, Parent, Sub and the Company desire to make certain representations,
warranties and agreements in connection with the Merger and also to prescribe
various conditions to the Merger.
 
  NOW, THEREFORE, in consideration of the premises and the representations,
warranties and agreements herein contained, the parties agree as follows:
 
                                   ARTICLE I
 
                                   The Merger
 
  Section 1.1 The Merger. Upon the terms and subject to the conditions hereof,
and in accordance with the General Corporation Law of the State of Delaware
(the "DGCL"), Sub shall be merged with and into the Company at the Effective
Time (as hereinafter defined). At the election of Parent, any direct wholly-
owned subsidiary of Parent may be substituted for Sub as a constituent
corporation in the Merger. In such event, the parties agree to execute an
appropriate amendment to this Agreement in order to reflect the foregoing.
Following the Merger, the separate corporate existence of Sub shall cease and
the Company shall continue as the surviving corporation (the "Surviving
Corporation") and shall succeed to and assume all the rights and obligations of
Sub in accordance with the DGCL. Notwithstanding the foregoing, Sub may elect
at any time prior to the Merger, instead of merging into the Company as
provided above, to merge the Company with and into Sub; provided, however, that
the Company shall not be deemed to have breached any of its representations,
warranties or covenants herein solely by reason of such election. In such
event, the parties agree to execute an appropriate amendment to this Agreement
in order to reflect the foregoing and, where appropriate, to provide that Sub
shall be the Surviving Corporation and will continue under the name "Plains
Petroleum Company."
 
  Section 1.2 Effective Time. The Merger shall become effective when the
Certificate of Merger (the "Certificate of Merger"), executed in accordance
with the relevant provisions of the DGCL, is filed with the Secretary of State
of the State of Delaware; provided, however, that, upon mutual consent of the
Constituent
 
- --------
* Now known as Barrett Energy Inc.
 
                                      I-5
<PAGE>
 
Corporations the Certificate of Merger may provide for a later date of
effectiveness of the Merger not more than 30 days after the date the
Certificate of Merger is filed. When used in this Agreement, the term
"Effective Time" shall mean the later of the date and time at which the
Certificate of Merger is accepted for record or such later time established by
the Certificate of Merger. The filing of the Certificate of Merger shall be
made as soon as practicable after the satisfaction or waiver of the conditions
to the Merger set forth herein.
 
  Section 1.3 Effects of the Merger. The Merger shall have the effects set
forth in Section 259 of the DGCL.
 
  Section 1.4 Certificate of Incorporation, By-laws and Directors. The
Certificate of Incorporation and By-laws of Sub, as in effect immediately prior
to the Effective Time, shall be the Certificate of Incorporation and By-laws of
the Surviving Corporation until thereafter changed or amended as provided
therein or by applicable law. The directors of Sub at the Effective Time shall
be the directors of the Surviving Corporation until their respective successors
have been duly elected or appointed in accordance with the Certificate of
Incorporation and By-laws of the Surviving Corporation or by applicable law.
 
  Section 1.5 Conversion of Securities. As of the Effective Time, by virtue of
the Merger and without any action on the part of any stockholder of the
Company:
 
    (a) All shares of Company Common Stock, and the associated Preferred
  Stock Purchase Rights (the "Rights") issued pursuant to the Rights
  Agreement, dated as of May 12, 1988, as amended (the "Rights Agreement"),
  between the Company and Chemical Bank (successor to the Manufacturers
  Hanover Trust Company), as Rights Agent, that are held in the treasury of
  the Company or by any wholly-owned Subsidiary (as hereinafter defined) of
  the Company and any shares of Company Common Stock (and associated Rights)
  owned by Parent, Sub or any other wholly-owned Subsidiary of Parent shall
  be cancelled and no capital stock of Parent or other consideration shall be
  delivered in exchange therefor.
 
    (b) Each issued and outstanding share of capital stock of Sub shall be
  converted into and become one fully paid and nonassessable share of Common
  Stock, par value $.01 per share, of the Surviving Corporation.
 
    (c) Subject to the provisions of Sections 1.8 and 1.10 hereof, each share
  of Company Common Stock (and associated Right) issued and outstanding
  immediately prior to the Effective Time (other than shares (and associated
  Rights) to be cancelled in accordance with Section 1.5(a)) shall be
  converted into 1.30 shares (the "Exchange Ratio") of validly issued, fully
  paid and nonassessable shares of Parent Common Stock. All such shares of
  Company Common Stock (and associated Rights), when so converted, shall no
  longer be outstanding and shall automatically be cancelled and retired and
  each holder of a Certificate (as defined in Section 1.6(a)) representing
  any such shares (and associated Rights) shall cease to have any rights with
  respect thereto, except the right to receive certain dividends and other
  distributions as contemplated by Section 1.7 and shares of Parent Common
  Stock and any cash, without interest, in lieu of fractional shares to be
  issued or paid in consideration therefor upon the surrender of such
  Certificate in accordance with Section 1.6.
 
  Section 1.6 Parent to Make Certificates Available.
 
  (a) Exchange of Certificates. Parent and the Company shall authorize The Bank
of Boston (or such other person or persons as shall be reasonably acceptable to
Parent and the Company) to act as Exchange Agent hereunder (the "Exchange
Agent"). As soon as practicable after the Effective Time, Parent shall deposit
with the Exchange Agent for the benefit of the holders of certificates which
immediately prior to the Effective Time represented shares of Company Common
Stock (and associated Rights) (the "Certificates") certificates representing
the shares of Parent Common Stock (such shares of Parent Common Stock, together
with any dividends or distributions with respect thereto payable as provided in
Section 1.7, being hereinafter referred to as the "Exchange Fund") issuable
pursuant to Section 1.5(c) in exchange for outstanding shares of Company Common
Stock (and associated Rights).
 
                                      I-6
<PAGE>
 
  (b) Exchange Procedures. As soon as practicable after the Effective Time, the
Exchange Agent shall mail to each holder of record of a Certificate whose
shares (and associated Rights) were converted pursuant to Section 1.5 into
shares of Parent Common Stock a letter of transmittal (which shall specify that
delivery shall be effected, and risk of loss and title to the Certificates
shall pass, only upon actual and proper delivery of the Certificates to the
Exchange Agent and shall contain instructions for use in effecting the
surrender of the Certificates in exchange for certificates representing shares
of Parent Common Stock and shall be in such form and contain such other
provisions as Parent and the Company may reasonably specify). Upon surrender of
a Certificate for cancellation to the Exchange Agent, together with such letter
of transmittal, duly executed, the holder of such Certificate shall be entitled
to receive in exchange therefor a certificate representing that number of whole
shares of Parent Common Stock which such holder has the right to receive
pursuant to this Article I, and the Certificate so surrendered shall forthwith
be cancelled. Until surrendered as contemplated by this Section 1.6, each
Certificate shall, at and after the Effective Time, be deemed to represent only
the right to receive, upon surrender of such Certificate, the certificate
representing the appropriate number of shares of Parent Common Stock, cash in
lieu of fractional shares as contemplated by Section 1.8 and certain dividends
and other distributions as contemplated by Section 1.7.
 
  Section 1.7 Dividends; Transfer Taxes. No dividends or other distributions
that are declared on or after the Effective Time on Parent Common Stock or are
payable to the holders of record thereof on or after the Effective Time will be
paid to persons entitled by reason of the Merger to receive certificates
representing Parent Common Stock until such persons surrender their
Certificates, as provided in Section 1.6, and no cash payment in lieu of
fractional shares shall be paid to any such holder pursuant to Section 1.8
until such holder of such Certificate shall so surrender such Certificate.
Subject to the effect of applicable law, there shall be paid to the record
holder of the certificates representing such Parent Common Stock (i) at the
time of such surrender or as promptly as practicable thereafter, the amount of
any dividends or other distributions theretofore paid with respect to whole
shares of such Parent Common Stock and having a record date on or after the
Effective Time and a payment date prior to such surrender and (ii) at the
appropriate payment date or as promptly as practicable thereafter, the amount
of dividends or other distributions payable with respect to whole shares of
Parent Common Stock and having a record date on or after the Effective Time but
prior to surrender and a payment date subsequent to surrender. In no event
shall the person entitled to receive such dividends or other distributions be
entitled to receive interest on such dividends or other distributions. If any
cash or certificate representing shares of Parent Common Stock is to be paid to
or issued in a name other than that in which the Certificate surrendered in
exchange therefor is registered, it shall be a condition of such exchange that
the Certificate so surrendered shall be properly endorsed and otherwise in
proper form for transfer and that the person requesting such exchange shall pay
to the Exchange Agent any transfer or other taxes required by reason of the
issuance of certificates for such shares of Parent Common Stock in a name other
than that of the registered holder of the Certificate surrendered, or shall
establish to the satisfaction of the Exchange Agent that such tax has been paid
or is not applicable.
 
  Section 1.8 No Fractional Securities. No certificates or scrip representing
fractional shares of Parent Common Stock shall be issued upon the surrender for
exchange of Certificates pursuant to this Article I, and no Parent dividend or
other distribution or stock split or combination shall relate to any fractional
security, and such fractional interests shall not entitle the owner thereof to
vote or to any rights of a security holder of Parent. In lieu of any such
fractional securities, each holder of shares of Company Common Stock who would
otherwise have been entitled to receive a fraction of a share of Parent Common
Stock (after taking into account all shares of Company Common Stock then held
of record by such holder) shall receive cash (without interest) in an amount
equal to the product of such fractional part of a share of Company Common Stock
multiplied by the Closing Price. As used in this Agreement, (i) "Closing Price"
means the average of the midpoint of the daily high and low trading prices of
Parent Common Stock, rounded to four decimal places, as reported under New York
Stock Exchange Composite Transactions Reports in The Wall Street Journal for
each of the first 20 consecutive Trading Days in the period commencing 25
Trading Days prior to the date of the Closing and (ii) "Trading Day" means a
day on which the New York Stock Exchange, Inc. (the "NYSE") is open for
trading.
 
                                      I-7
<PAGE>
 
  Section 1.9 Return of Exchange Fund. Any portion of the Exchange Fund which
remains undistributed to the former stockholders of the Company for one year
after the Effective Time shall be delivered to Parent, upon demand of Parent,
and any former stockholders of the Company who have not theretofore complied
with this Article I shall thereafter look only to Parent for payment of their
claim for Parent Common Stock, any cash in lieu of fractional shares of Parent
Common Stock and any dividends or distributions with respect to Parent Common
Stock. None of Parent, the Company or the Surviving Corporation shall be liable
to any holder of shares of Company Common stock (and associated Rights) for
shares (or dividends or distributions with respect thereto) or cash in lieu of
fractional shares of Parent Common Stock delivered to a public official
pursuant to any applicable abandoned property, escheat or similar law.
 
  Section 1.10 Adjustment of Exchange Ratio. Subject to Section 5.1(a), in the
event of any reclassification, recapitalization, stock split, stock
combination, stock dividend or share exchange with respect to Parent Common
Stock or Company Common Stock, as the case may be, (or if a record date with
respect to any of the foregoing should occur) prior to the Effective Time,
appropriate and proportionate adjustments, if any, shall be made to the
Exchange Ratio, and all references to the Exchange Ratio in this Agreement
shall be deemed to be to the Exchange Ratio as so adjusted.
 
  Section 1.11 No Further Ownership Rights in Company Common Stock. All shares
of Parent Common Stock issued upon the surrender for exchange of Certificates
in accordance with the terms hereof (including any cash paid pursuant to
Sections 1.7 or 1.8) shall be deemed to have been issued in full satisfaction
of all rights pertaining to the shares of Company Common Stock (and associated
Rights), subject, however, to the Surviving Corporation's obligation to pay any
dividends or make any other distribution with a record date prior to the
Effective Time which may have been declared or made by the Company on such
shares of Company Common Stock in accordance with the terms of this Agreement.
 
  Section 1.12 Closing of Company Transfer Books. At the Effective Time, the
stock transfer books of the Company shall be closed and no transfer of shares
of Company Common Stock (and associated Rights) shall thereafter be made. If,
after the Effective Time, Certificates are presented to the Surviving
Corporation, they shall be cancelled and exchanged as provided in this Article
I.
 
  Section 1.13 Further Assurances. If at any time after the Effective Time the
Surviving Corporation shall consider or be advised that any deeds, bills of
sale, assignments or assurances or any other acts or things are necessary,
desirable or proper (a) to vest, perfect or confirm, of record or otherwise, in
the Surviving Corporation, its right, title or interest in, to or under any of
the rights, privileges, powers, franchises, properties or assets of either of
the Constituent Corporations, or (b) otherwise to carry out the purposes of
this Agreement, the Surviving Corporation and its proper officers and directors
or their designees shall be authorized to execute and deliver, in the name and
on behalf of either of the Constituent Corporations in the Merger, all such
deeds, bills of sale, assignments and assurances and do, in the name and on
behalf of such Constituent Corporations, all such other acts and things
necessary, desirable or proper to vest, perfect or confirm its right, title or
interest in, to or under any of the rights, privileges, powers, franchises,
properties or assets of such Constituent Corporation and otherwise to carry out
the purposes of this Agreement.
 
  Section 1.14 Closing. The closing of the transactions contemplated by this
Agreement (the "Closing") shall take place at the offices of Bearman Talesnick
& Clowdus Professional Corporation, 1200 Seventeenth Street, Suite 2600,
Denver, Colorado, at 10:00 a.m. local time, on the second business day after
the day on which the last of the conditions set forth in Article VII hereof
shall have been fulfilled or waived or at such other time and place as Parent
and the Company shall agree.
 
 
                                      I-8
<PAGE>
 
                                   ARTICLE II
 
                    Representations and Warranties of Parent
 
  Parent represents and warrants to the Company as follows:
 
  Section 2.1 Organization, Standing and Power. Parent is a corporation duly
incorporated, validly existing and in good standing under the laws of the State
of Delaware and has the requisite corporate power and authority to carry on its
business as now being conducted. Parent and each of its Significant
Subsidiaries (as hereinafter defined) is duly qualified to do business, and is
in good standing, in each jurisdiction where the character of its properties
owned or held under lease or the nature of its activities makes such
qualification necessary, except where the failure to be so qualified would not,
individually or in the aggregate, have a Material Adverse Effect on Parent. For
purposes of this Agreement (a) "Material Adverse Change" or "Material Adverse
Effect" means, when used with respect to Parent or the Company, as the case may
be, any change or effect that is or, so far as can reasonably be determined, is
likely to be materially adverse to the assets, properties, condition (financial
or otherwise), business or results of operations of Parent and its Significant
Subsidiaries taken as a whole or the Company and its Significant Subsidiaries
taken as a whole, as the case may be, (b) "Subsidiary" means any corporation,
partnership, joint venture or other legal entity of which Parent or the
Company, as the case may be (either alone or through or together with any other
Subsidiary), owns, directly or indirectly, 50% or more of the stock or other
equity interests the holders of which are generally entitled to vote for the
election of the board of directors or other governing body of such corporation
or other legal entity and (c) "Significant Subsidiary" means any Significant
Subsidiary within the meaning of Rule 1-02 of Regulation S-X of the United
States Securities and Exchange Commission (the "SEC").
 
  Section 2.2 Capital Structure. As of the date hereof, the authorized capital
stock of Parent consists of 17,000,000 shares of Parent Common Stock and
1,000,000 shares of Preferred Stock, par value $.001 per share ("Parent
Preferred Stock"). At the close of business on April 28, 1995 (i) 11,956,238
shares of Parent Common Stock were validly issued and outstanding, fully paid
and nonassessable and free of preemptive rights, (ii) 704,500 shares of Parent
Common Stock were reserved for issuance upon the exercise of outstanding
options for Parent Common Stock, (iii) 228,500 shares of Parent Common Stock
were reserved for issuance under Parent's 1990 Stock Option Plan, the 1994
Stock Option Plan and the Non-Discretionary Stock Option Plan, (iv) 1,322
shares of Parent Common Stock were held by Parent in its treasury and (v) no
shares of Parent Preferred Stock were issued and outstanding. There are no
outstanding stock appreciation rights ("SARs"). All of the shares of Parent
Common Stock issuable in exchange for Company Common Stock (and associated
Rights) at the Effective Time in accordance with this Agreement will be, when
so issued, duly authorized, validly issued, fully paid and nonassessable and
free of preemptive rights and will be, subject to official notice of issuance,
either listed on a national securities exchange or designated as a national
market system security on an interdealer quotation system by the National
Association of Securities Dealers, Inc. ("Nasdaq") or held of record by more
than 2,000 stockholders. Except for options granted pursuant to Parent's 1990
Stock Option Plan, the 1994 Stock Option Plan and the Non-Discretionary Stock
Option Plan, there are no options, warrants, rights, commitments, agreements,
arrangements or undertakings of any kind to which Parent or any of its
Significant Subsidiaries is a party or by which any of them is bound obligating
Parent or any of its Significant Subsidiaries to issue, deliver or sell, or
cause to be issued, delivered or sold, additional shares of capital stock or
other voting securities of Parent or of any of its Significant Subsidiaries.
True and correct copies of all agreements, instruments and other governing
documents relating to the Parent's 1990 Stock Option Plan, the 1994 Stock
Option Plan and the Non-Discretionary Stock Option Plan have been furnished to
the Company.
 
  Section 2.3 Authority; Non-Contravention. The Board of Directors of Parent
has declared fair to and advisable and in the best interests of the
stockholders of Parent an amendment to Parent's Certificate of Incorporation to
increase the number of authorized shares of Parent Common Stock to 35,000,000
shares (the "Charter Amendment") and the issuance of shares of Parent Common
Stock pursuant to the Merger
 
                                      I-9
<PAGE>
 
(the "Share Issuance"). Parent has all requisite power and authority to enter
into this Agreement and, subject to the approval of the Charter Amendment and
the Share Issuance by the stockholders of Parent, to consummate the
transactions contemplated hereby. The execution and delivery of this Agreement
by Parent and the consummation by Parent of the transactions contemplated
hereby have been duly authorized by all necessary corporate action on the part
of Parent, subject to such approval of the Charter Amendment and the Share
Issuance by the stockholders of Parent. This Agreement has been duly executed
and delivered by Parent and (assuming the valid authorization, execution and
delivery of this Agreement by the Company) constitutes a valid and binding
obligation of Parent enforceable against Parent in accordance with its terms,
except to the extent enforceability may be limited by bankruptcy, insolvency,
reorganization, moratorium, fraudulent transfer or other similar laws of
general applicability relating to or affecting the enforcement of creditors'
rights and by the effect of general principles of equity (regardless of whether
enforceability is considered in a proceeding in equity or at law). The Charter
Amendment, the Share Issuance and the filing of a registration statement with
the SEC by Parent on Form S-4 under the Securities Act of 1933, as amended
(together with the rules and regulations promulgated thereunder, the
"Securities Act"), for the purpose of registering the shares of Parent Common
Stock to be issued in the Merger (together with any amendments or supplements
thereto, the "Registration Statement") has been duly authorized by Parent's
Board of Directors. Except as set forth in Section 2.3 of the disclosure
statement of Parent dated as of the date hereof previously furnished to the
Company (the "Parent Disclosure Schedule"), the execution and delivery of this
Agreement do not, and the consummation of the transactions contemplated hereby
and compliance with the provisions hereof will not, conflict with, or result in
any violation of, or default (with or without notice or lapse of time, or both)
under, or give rise to a right of termination, cancellation or acceleration of
any obligation or to the loss of a material benefit under, or result in the
creation of any lien, security interest, charge or encumbrance upon any of the
properties or assets of Parent or any of its Significant Subsidiaries under,
any provision of (i) the Certificate of Incorporation or By-laws (true and
complete copies of which as of the date hereof have been delivered to the
Company) of Parent or any provision of the comparable charter or organization
documents of any of its Significant Subsidiaries, (ii) any loan or credit
agreement, note, bond, mortgage, indenture, lease or other agreement,
instrument, permit, concession, franchise or license applicable to Parent or
any of its Significant Subsidiaries or (iii) any judgment, order, decree,
statute, law, ordinance, rule or regulation applicable to Parent or any of its
Significant Subsidiaries or any of their respective properties or assets, other
than, in the case of clauses (ii) or (iii), any such conflicts, violations,
defaults, rights, liens, security interests, charges or encumbrances that,
individually or in the aggregate, would not have a Material Adverse Effect on
Parent, materially impair the ability of Parent to perform its obligations
hereunder or prevent the consummation of any of the transactions contemplated
hereby. Except as set forth on Section 2.3 of the Parent Disclosure Schedule,
no filing or registration with, or authorization, consent or approval of, any
domestic (federal and state), foreign or supranational court, commission,
governmental body, regulatory agency, authority or tribunal (a "Governmental
Entity") is required by or with respect to Parent or any of its Significant
Subsidiaries in connection with the execution and delivery of this Agreement by
Parent or is necessary for the consummation of the Merger and the other
transactions contemplated by this Agreement, except for (i) in connection, or
in compliance, with the provisions of the Securities Act and the Securities
Exchange Act of 1934, as amended (together with the rules and regulations
promulgated thereunder, the "Exchange Act"), (ii) the filing of the Certificate
of Merger with the Secretary of State of the State of Delaware and appropriate
documents with the relevant authorities of other states in which the Company is
qualified to do business, (iii) such filings and consents as may be required
under any environmental, health or safety law or regulation pertaining to any
notification, disclosure or required approval triggered by the Merger or the
transactions contemplated by this Agreement, (iv) such filings as may be
required in connection with applicable taxes, (v) such consents, approvals,
orders, authorizations, registrations, declarations and filings as may be
required under the corporation, takeover or "Blue Sky" laws of various states,
(vi) such filings and approvals as may be required under the Hart-Scott-Rodino
Antitrust Improvements Act of 1976 (the "Improvements Act"), and (vii) such
other consents, orders, authorizations, registrations, declarations and filings
the failure of which to be obtained or made would not, individually or in the
aggregate, have a Material Adverse Effect on Parent, materially impair the
ability of Parent to perform its obligations hereunder or prevent the
consummation of any of the transactions contemplated hereby.
 
                                      I-10
<PAGE>
 
  Section 2.4 SEC Documents. Parent has filed all required documents with the
SEC since January 1, 1993 (the "Parent SEC Documents"). As of their respective
dates, the Parent SEC Documents complied in all material respects with the
requirements of the Securities Act or the Exchange Act, as the case may be, and
none of the Parent SEC Documents contained any untrue statement of a material
fact or omitted to state a material fact required to be stated therein or
necessary to make the statements therein, in light of the circumstances under
which they were made, not misleading. The financial statements of Parent
included in the Parent SEC Documents comply as to form in all material respects
with applicable accounting requirements and the published rules and regulations
of the SEC with respect thereto, have been prepared in accordance with
generally accepted accounting principles (except, in the case of the unaudited
statements, as permitted by Form 10-Q of the SEC) applied on a consistent basis
during the periods involved (except as may be indicated therein or in the notes
thereto) and fairly present the consolidated financial position of Parent and
its consolidated Subsidiaries as at the dates thereof and the consolidated
results of their operations and statements of cash flows for the periods then
ended (subject, in the case of unaudited statements, to normal year-end audit
adjustments and to any other adjustments described therein). There is no
liability or obligation of any kind, whether accrued, absolute, fixed or
contingent, of Parent or any Subsidiary of Parent of which the executive
officers of Parent have knowledge and which is required by generally accepted
accounting principles to be reflected or reserved against or otherwise
disclosed in the most recent financial statements of Parent included in the
Parent SEC Documents which is not so reflected or reserved against that
individually or in the aggregate would have a Material Adverse Effect on
Parent.
 
  Section 2.5 Engineering Reports. All information supplied to Ryder Scott
Company by or on behalf of Parent and its Subsidiaries that was material to
such firm's review of Parent's estimates of oil and gas reserves attributable
to the Oil and Gas Interests of Parent and its Subsidiaries in connection with
the preparation of the oil and gas reserve engineering report concerning the
Oil and Gas Interests of Parent and its Subsidiaries as of September 30, 1994
reviewed by Ryder Scott Company (the "Parent Engineering Report") was (at the
time supplied or as modified or amended prior to the issuance of the Parent
Engineering Report) true and correct in all material respects. For purposes of
this Agreement "Oil and Gas Interests" means, when used with respect to Parent
or the Company or each of their respective Subsidiaries, as the case may be,
direct and indirect interests in and rights with respect to oil, gas, helium,
carbon dioxide, mineral, and related properties and assets of any kind and
nature, direct or indirect, including working, royalty, and overriding royalty
interests, production payments, operating rights, net profit interests, other
nonworking interests, and nonoperating interests; all interests in and rights
with respect to oil, condensate, gas, casinghead gas, helium, carbon dioxide
and other liquid or gaseous hydrocarbons (collectively, "Hydrocarbons") and
other minerals or revenues therefrom and all contracts in connection therewith
and claims and rights thereto (including all oil and gas leases, operating
agreements, unitization and pooling agreements and orders, division orders,
transfer orders, mineral deeds, royalty deeds, oil and gas sales, exchange and
processing contracts and agreements, and in each case, interests thereunder),
surface interests, fee interests, reversionary interests, reservations, and
concessions; all easements, rights of way, licenses, permits, leases, and other
interests associated with, appurtenant to, or necessary for the operation of
any of the foregoing; and all interests in equipment and machinery (including
well equipment and machinery), oil and gas production, gathering,
transmissions, treating, processing, and storage facilities (including tanks,
tank batteries, pipelines, and gathering systems), pumps, water plants,
electric plants, gasoline and gas processing plants, refineries, and other
tangible personal property and fixtures associated with, appurtenant to, or
necessary for the operation of any of the foregoing. Except for changes in
classification or values of oil and gas reserve or property interests that
occurred in the ordinary course of business since September 30, 1994, and
except for changes (including changes in commodity prices) generally affecting
the oil and gas industry on a nationwide basis, there has been no Material
Adverse Change in respect of Parent regarding the matters addressed in the
Parent Engineering Report.
 
  Section 2.6 Oil and Gas Reserve Information. Except as otherwise set forth in
Section 2.6 of the Parent Disclosure Schedule:
 
 
                                      I-11
<PAGE>
 
    (a) None of the wells included in the Oil and Gas Interests of Parent and
  its Subsidiaries has been overproduced such that it is subject or liable to
  being shut-in or to any other overproduction penalty, except where any such
  overproduction would not have a Material Adverse Effect on Parent;
 
    (b) There have been no changes proposed in the production allowables for
  any wells included in the Oil and Gas Interests of Parent and its
  Subsidiaries that would have a Material Adverse Effect on Parent;
 
    (c) All wells included in the Oil and Gas Interests of Parent and its
  Subsidiaries have been drilled and (if completed) completed, operated, and
  produced in accordance with good oil and gas field practices and in
  compliance in all material respects with applicable oil and gas leases and
  applicable laws, rules, and regulations, except where any failure or
  violation would not have a Material Adverse Effect on Parent;
 
    (d) Neither Parent nor its Subsidiaries has agreed to or is now obligated
  to abandon any well included in the Oil and Gas Interests of Parent and its
  Subsidiaries that is not or will not be abandoned and reclaimed in
  accordance with the applicable laws, rules, and regulations and good oil
  and gas industry practices, except where any abandonment would not have a
  Material Adverse Effect on Parent;
 
    (e) Proceeds from the sale of Hydrocarbons produced from the Oil and Gas
  Interests of Parent and its Subsidiaries are being received by Parent and
  its Subsidiaries in a timely manner and are not being held by third parties
  in suspense for any reason (except for amounts, individually or in the
  aggregate, not in excess of $1,000,000 and held in suspense in the ordinary
  course of business); and
 
    (f) No person has any call on, option to purchase, or similar rights with
  respect to the Oil and Gas Interests of Parent and its Subsidiaries or to
  the production attributable thereto, and upon consummation of the
  transactions contemplated by this Agreement, Parent or its Subsidiaries
  will have the right to market production from the Oil and Gas Interests of
  Parent and its Subsidiaries on terms no less favorable than the terms upon
  which such company is currently marketing such production, except where any
  call or option would not have a Material Adverse Effect on Parent.
 
  Section 2.7 Registration Statement and Proxy Statement. None of the
information to be supplied by Parent or Sub for inclusion or incorporation by
reference in the Registration Statement or the proxy statement (together with
any amendments or supplements thereto, the "Proxy Statement") relating to the
Stockholder Meetings (as defined in Section 6.1) will (i) in the case of the
Registration Statement, at the time it becomes effective and at the Effective
Time, contain any untrue statement of a material fact or omit to state any
material fact required to be stated therein or necessary in order to make the
statements therein not misleading or (ii) in the case of the Proxy Statement,
at the time of the mailing of the Proxy Statement and at the time of the
Stockholder Meetings, contain any untrue statement of a material fact or omit
to state any material fact required to be stated therein or necessary in order
to make the statements therein, in light of the circumstances under which they
are made, not misleading. If at any time prior to the Effective Time any event
with respect to Parent, its officers and directors or any of its Subsidiaries
shall occur which is required to be described in the Proxy Statement or the
Registration Statement, such event shall be so described, and an amendment or
supplement shall be promptly filed with the SEC and, as required by law,
disseminated to the stockholders of the Company and Parent. The Registration
Statement will comply (with respect to Parent and Sub) as to form in all
material respects with the provisions of the Securities Act, and the Proxy
Statement will comply (with respect to Parent and Sub) as to form in all
material respects with the provisions of the Exchange Act.
 
  Section 2.8 Absence of Material Adverse Change. Except as disclosed in the
Parent SEC Documents filed with the SEC prior to the date hereof, there has not
been any Material Adverse Change with respect to Parent (other than changes in
generally accepted accounting principles or interpretations thereof that affect
the oil and gas industry generally or changes in general economic conditions
that affect the oil and gas industry on a nationwide basis).
 
  Section 2.9 Pooling of Interests; Reorganization. To the knowledge of Parent,
neither Parent nor Sub has (i) taken any action or failed to take any action
which action or failure to take action would jeopardize
 
                                      I-12
<PAGE>
 
the treatment of Sub's combination with the Company in the Merger as a pooling
of interests for accounting purposes or (ii) taken any action or failed to take
any action which action or failure to take action would jeopardize the
qualification of the Merger as a reorganization within the meaning of Section
368(a) of the Code. Without limiting the foregoing: (i) Sub is wholly owned
directly by Parent, and Sub has never owned or held any assets and has never
incurred any liabilities, except for assets transferred to Sub in connection
with its incorporation, all of which assets will be held by the Surviving
Corporation immediately following the Merger, (ii) Parent has no plan or
intention: to cause the Surviving Corporation to issue any shares of stock
following the Merger, to reacquire any of the Parent Common Stock issued in the
Merger, to liquidate the Surviving Corporation, to merge the Surviving
Corporation with or into another corporation, to sell or otherwise dispose of
any stock of the Surviving Corporation, or to cause the Surviving Corporation
to sell or otherwise dispose of (except in the ordinary course of business) any
of its assets, (iii) following the Merger, the Surviving Corporation will
continue at least one significant historic business line of the Company, or use
at least a significant portion of the Company's historic business assets in a
business, in each case within the meaning of Treas. Reg. (S) 1.368-1(d) and
(iv) neither Parent nor any of its Subsidiaries own, nor have any of them owned
during the past five years, any capital stock of the Company.
 
  Section 2.10 Taxes. Except as otherwise set forth in Section 2.10 of the
Parent Disclosure Schedule, (i) Parent and each Significant Subsidiary has
filed all material Tax Returns required to have been filed on or before the
date hereof or extensions have been duly obtained; (ii) all Taxes shown to be
due on the Tax Returns referred to in clause (i) have been timely paid or
extensions have been duly obtained or such taxes have been adequately provided
for or are being timely and properly contested; (iii) neither Parent nor any
Significant Subsidiary has waived any statute of limitations in respect of
Taxes of Parent or such Subsidiary; (iv) the Tax Returns referred to in clause
(i) relating to federal and state income Taxes have been examined by the
Internal Revenue Service or the appropriate state taxing authority or the
period for assessment of the Taxes in respect of which such Tax Returns were
required to be filed has expired; (v) no issues that have been raised in
writing by the relevant taxing authority in connection with the examination of
the Tax Returns referred to in clause (i) are currently pending; (vi) all
deficiencies asserted or assessments made as a result of any examination of the
Tax Returns referred to in clause (i) by a taxing authority have been paid in
full or adequately provided for or are being timely and properly contested; and
(vii) neither Parent nor any Significant Subsidiary of Parent is a party to an
income Tax allocation or sharing agreement with respect to a group of
corporations filing tax returns on a combined, consolidated or unitary basis.
For purposes of this Agreement, (a) "Tax" (and, with correlative meaning,
"Taxes" and "Taxable") means any federal, state, local or foreign income, gross
receipts, property, sales, use, license, excise, franchise, employment,
payroll, withholding, alternative or added minimum, ad valorem, transfer or
excise tax, or any other tax, custom, duty, governmental fee or other like
assessment or charge of any kind whatsoever, together with any interest or
penalty, imposed by any governmental authority and (b) "Tax Return" means any
return, report or similar statement required to be filed with respect to any
Tax (including any attached schedules), including, without limitation, any
information return, claim for refund, amended return or declaration of
estimated Tax.
 
  Section 2.11 Title to Property. Except as set forth on Section 2.11 of the
Parent Disclosure Schedule, Parent or its Subsidiaries has good and, with
respect to real property, marketable title to all of the material assets
reflected on the consolidated financial statements of Parent included in the
Parent SEC Documents as being owned by it or its Subsidiaries and all of the
material assets thereafter acquired by it or its Subsidiaries (except to the
extent that such assets have thereafter been disposed of in the ordinary course
of business consistent with past practice), subject to no liens, mortgages,
pledges, security interests, encumbrances, claims or charges of any kind
(collectively, "Liens") except for (i) Liens for taxes not yet delinquent or
the validity of which is being contested in good faith and (ii) any Liens
arising by operation of law securing obligations not yet overdue.
Notwithstanding the foregoing, title to the Oil and Gas Interests of Parent and
its Subsidiaries is of the type customarily acceptable to prudent investors in
Oil and Gas Interests in the area where such Oil and Gas Interests of Parent
and its Subsidiaries are located.
 
  Section 2.12 Employee Benefit Plans. With respect to all the employee benefit
plans, programs and arrangements maintained for the benefit of any current or
former employee, officer or director of Parent or
 
                                      I-13
<PAGE>
 
any Subsidiary of Parent (collectively, the "Parent Plans"), except as set
forth in the Parent SEC Documents and except as would not, individually or in
the aggregate, have a Material Adverse Effect on Parent: (i) none of the Parent
Plans is a multiemployer plan within the meaning of the Employee Retirement
Income Security Act of 1974, as amended ("ERISA"); (ii) none of the Parent
Plans promises or provides retiree medical or life insurance benefits to any
person, except as otherwise required by law in the applicable jurisdiction and,
outside of the United States, in accordance with local custom and practice;
(iii) each Parent Plan intended to be qualified under Section 401(a) of the
Code has received a favorable determination letter from the Internal Revenue
Service that it is so qualified and nothing has occurred since the date of such
letter that could reasonably be expected to affect the qualified status of such
Parent Plan; (iv) each Parent Plan has been operated in all respects in
accordance with its terms and the requirements of applicable law; (v) neither
Parent nor any Subsidiary of Parent has incurred any direct or indirect
liability under, arising out of or by operation of Title IV of ERISA in
connection with the termination of, or withdrawal from, any Parent Plan or
other retirement plan or arrangement, and no fact or event exists that could
reasonably be expected to give rise to any such liability; and (vi) Parent and
its Subsidiaries have not incurred any liability under, and have complied in
all respects with, the Worker Adjustment Retraining Notification Act, and no
fact or event exists that could give rise to liability under such Act. Except
as set forth in the Parent SEC Documents, the aggregate accumulated benefit
obligations of each Parent Plan subject to Title IV of ERISA (as of the date of
the most recent actuarial valuation prepared for such Parent Plan) do not
exceed the fair market value of the assets of such Parent Plan (as of the date
of such valuation).
 
  Section 2.13 Labor Matters. (a) Neither Parent nor any of its Significant
Subsidiaries is a party to any collective bargaining agreement or other
material contract or agreement with any labor organization or other
representative of employees nor is any such contract being negotiated; (b)
there is no material unfair labor practice charge or complaint pending nor, to
the knowledge of the executive officers of Parent, threatened, with regard to
employees of Parent or any Significant Subsidiary; (c) there is no labor
strike, material slowdown, material work stoppage or other material labor
controversy in effect, or, to the knowledge of the executive officers of
Parent, threatened against Parent or any of its Significant Subsidiaries; (d)
as of the date hereof, no representation question exists, nor to the knowledge
of the executive officers of Parent are there any campaigns being conducted to
solicit cards from the employees of Parent or any Significant Subsidiary of
Parent to authorize representation by any labor organization; (e) neither
Parent nor any Significant Subsidiary of Parent is a party to, or is otherwise
bound by, any consent decree with any governmental authority relating to
employees or employment practices of Parent or any Significant Subsidiary of
Parent; and (f) Parent and each Significant Subsidiary of Parent are in
compliance with all applicable agreements, contracts and policies relating to
employment, employment practices, wages, hours and terms and conditions of
employment of the employees, except where the failure to be in compliance with
each such agreement, contract and policy would not, either singly or in the
aggregate, have a Material Adverse Effect on Parent.
 
  Section 2.14 Environmental Matters. (a) Except as set forth on Section 2.14
of the Parent Disclosure Schedule and except to the extent that the inaccuracy
of any of the following, individually or in the aggregate, would not have a
Material Adverse Effect on Parent, to the knowledge of the executive officers
of Parent:
 
    (i) Parent and its Subsidiaries hold, and are in compliance with and have
  been compliance with for the last two years, all Environmental Permits, and
  are otherwise in substantial compliance and have been in substantial
  compliance for the last two years with, all applicable Environmental Laws
  and there is no condition that is reasonably likely to prevent or
  materially interfere prior to the Effective Time with compliance by Parent
  and its Subsidiaries with Environmental Laws;
 
    (ii) no modification, revocation, reissuance, alteration, transfer or
  amendment of any Environmental Permit, or any review by, or approval of,
  any third party of any Environmental Permit is required in connection with
  the execution or delivery of this Agreement or the consummation by Parent
  of the transactions contemplated hereby or the operation of the business of
  Parent or any of its Subsidiaries on the date of the Closing;
 
                                      I-14
<PAGE>
 
    (iii) neither Parent nor any of its Subsidiaries has received any
  Environmental Claim, nor has any Environmental Claim been threatened
  against Parent or any of its Subsidiaries;
 
    (iv) neither Parent nor any of its Subsidiaries has entered into, agreed
  to or is subject to any outstanding judgment, decree, order or consent
  arrangement with any governmental authority under any Environmental Laws,
  including without limitation those relating to compliance with any
  Environmental Laws or to the investigation, cleanup, remediation or removal
  of Hazardous Materials;
 
    (v) there are no circumstances that are reasonably likely to give rise to
  liability under any agreements with any person pursuant to which Parent or
  any Subsidiary of Parent would be required to defend, indemnify, hold
  harmless, or otherwise be responsible for any violation by or other
  liability or expense of such person, or alleged violation by or other
  liability or expense of such person, arising out of any Environmental Law;
  and
 
    (vi) there are no other circumstances or conditions that are reasonably
  likely to give rise to liability of Parent or any of its Subsidiaries under
  any Environmental Laws.
 
  (b) For purposes of this Agreement, the terms below shall have the following
meanings:
 
    "Environmental Claim" means any written complaint, notice, claim, demand,
  action, suit or judicial, administrative or arbitral proceeding by any
  person to Parent or any of its Subsidiaries (or, for purposes of Section
  3.14, the Company or any of its Subsidiaries) asserting liability or
  potential liability (including without limitation, liability or potential
  liability for investigatory costs, cleanup costs, governmental response
  costs, natural resource damages, property damage, personal injury, fines or
  penalties) arising out of, relating to, based on or resulting from (i) the
  presence, discharge, emission, release or threatened release of any
  Hazardous Materials at any location, (ii) circumstances forming the basis
  of any violation or alleged violation of any Environmental Laws or
  Environmental Permits, or (iii) otherwise relating to obligations or
  liabilities under any Environmental Law.
 
    "Environmental Permits" means all permits, licenses, registrations,
  exemptions and other governmental authorizations required under
  Environmental Laws for Parent or any of its Subsidiaries (or, for purposes
  of Section 3.14, the Company or any of its Subsidiaries) to conduct their
  operations as presently conducted.
 
    "Environmental Laws" means all applicable foreign, federal, state and
  local statutes, rules, regulations, ordinances, orders, decrees and common
  law relating in any manner to pollution or protection of the environment,
  to the extent and in the form that such exist at the date hereof.
 
    "Hazardous Materials" means all hazardous or toxic substances, wastes,
  materials or chemicals, petroleum (including crude oil or any fraction
  thereof) and petroleum products, asbestos and asbestos-containing
  materials, pollutants, contaminants and all other materials and substances,
  including but not limited to radioactive materials regulated pursuant to
  any Environmental Laws or that could result in liability under any
  Environmental Laws.
 
  Section 2.15 Litigation. Except as set forth in Section 2.15 of the Parent
Disclosure Schedule and except as disclosed prior to the date hereof in the
Parent SEC Documents, there is no suit, action, investigation or proceeding
pending or, to the knowledge of the executive officers of Parent, threatened
against Parent or any of its Subsidiaries at law or in equity before or by any
federal, state, municipal or other governmental department, commission, board,
bureau, agency or instrumentality, domestic or foreign, or before any
arbitrator of any kind, that would have a Material Adverse Effect on Parent or,
with respect to such matters that are pending or threatened as of the date
hereof, materially impair the ability of Parent to perform its obligations
hereunder or to consummate the transactions contemplated hereby, and there is
no judgment, decree, injunction, rule or order of any court, governmental
department, commission, board, bureau, agency, instrumentality or arbitrator to
which Parent or any of its Subsidiaries is subject that would have a Material
Adverse Effect on Parent or, with respect to such items that are outstanding
and applicable
 
                                      I-15
<PAGE>
 
as of the date hereof, materially impair the ability of Parent to perform its
obligations hereunder or to consummate the transactions contemplated hereby.
 
  Section 2.16 Governmental Licenses and Permits; Compliance with Law. Except
as disclosed prior to the date hereof in the Parent SEC Documents, since
December 31, 1994, neither Parent nor any of its Significant Subsidiaries has
received notice of any revocation or modification of any federal, state, local
or foreign governmental license, certification, tariff, permit, authorization
or approval, the revocation or modification of which would have a Material
Adverse Effect on Parent. To the knowledge of the executive officers of Parent,
the conduct of the business of each of Parent and its Subsidiaries complies
with all statutes, laws, regulations, ordinances, rules, judgments, orders,
decrees or arbitration awards applicable thereto, except for violations or
failures to comply, if any, that, individually or in the aggregate, would not
have a Material Adverse Effect on Parent.
 
  Section 2.17 Required Vote of Parent Stockholders. The affirmative vote of
the holders of not less than a majority of the outstanding shares of Parent
Common Stock is required to approve the Charter Amendment and the Share
Issuance. No other vote of the stockholders of Parent is required by law, the
Certificate of Incorporation or By-laws of Parent or otherwise in order for
Parent to consummate the Merger and the other transactions contemplated hereby.
 
  Section 2.18 Opinion of Financial Advisor. On the date hereof, Parent has
received the written opinion of Petrie Parkman & Co., Inc. to the effect that
the Merger is fair to the stockholders of Parent from a financial point of
view.
 
  Section 2.19 Brokers. No broker, investment banker or other person, other
than Petrie Parkman & Co., Inc., the fees and expenses of which will be paid by
Parent, is entitled to any broker's, finder's or other similar fee or
commission in connection with the transactions contemplated by this Agreement
based upon arrangements made by or on behalf of Parent or Sub. Parent has
previously delivered to the Company a true, correct and complete copy of any
engagement or fee agreement between Parent and its Subsidiaries, on the one
hand, and Petrie Parkman & Co., Inc. on the other.
 
                                  ARTICLE III
 
                 Representations and Warranties of the Company
 
  The Company represents and warrants to Parent and Sub as follows:
 
  Section 3.1 Organization, Standing and Power. The Company is a corporation
duly incorporated, validly existing and in good standing under the laws of the
State of Delaware and has the requisite corporate power and authority to carry
on its business as now being conducted. The Company and each of its Significant
Subsidiaries is duly qualified to do business, and is in good standing, in each
jurisdiction where the character of its properties owned or held under lease or
the nature of its activities makes such qualification necessary, except where
the failure to be so qualified would not, individually or in the aggregate,
have a Material Adverse Effect on the Company.
 
  Section 3.2 Capital Structure. The authorized capital stock of the Company
consists of 20,000,000 shares of Company Common Stock and 1,000,000 shares of
Preferred Stock, par value $.01 per share (the "Preferred Stock"). At the close
of business on April 28, 1995, (i) 9,828,533 shares of Company Common Stock
were issued and outstanding, (ii) 494,859 shares of Company Common Stock were
reserved for issuance upon the exercise of outstanding Company Stock Options
(as defined in Section 6.7), (iii) 18,201 shares of Company Common Stock were
held by the Company in its treasury, and (iv) 200,000 shares of Preferred Stock
were reserved for Series A Junior Participating Preferred Stock in connection
with the Rights Agreement. There are no outstanding SARs. All outstanding
shares of capital stock of the Company are validly issued, fully paid and
nonassessable and not subject to preemptive rights. Except for (i) the Company
 
                                      I-16
<PAGE>
 
Stock Options outstanding as of April 28, 1995, (ii) the obligations of the
Company under the Plains Petroleum Company 401(k) Plan and Trust (the "401(k)
Plan") and the Plains Petroleum Company Profit Sharing Plan and Trust (the
"Company Profit Sharing Plan"), and (iii) the Rights issued pursuant to the
Rights Agreement, there are no options, warrants, rights, commitments,
agreements, arrangements or undertakings of any kind to which the Company or
any of its Significant Subsidiaries is a party or by which any of them is bound
obligating the Company or any of its Significant Subsidiaries to issue, deliver
or sell, or cause to be issued, delivered or sold, additional shares of capital
stock or other voting securities of the Company or of any of its Significant
Subsidiaries. True and correct copies of all agreements, instruments and other
governing documents relating to the 401(k) Plan and the Company Profit Sharing
Plan have been furnished to Parent.
 
  Section 3.3 Authority; Non-Contravention. The Board of Directors of the
Company has declared the Merger fair to and advisable and in the best interest
of the stockholders of the Company, and the Company has all requisite power and
authority to enter into this Agreement and, subject to approval of the Merger
by the stockholders of the Company, to consummate the transactions contemplated
hereby. The execution and delivery of this Agreement by the Company and the
consummation by the Company of the transactions contemplated hereby have been
duly authorized by all necessary corporate action on the part of the Company,
subject to such approval of the Merger by the stockholders of the Company. This
Agreement has been duly executed and delivered by the Company and (assuming the
valid authorization, execution and delivery of this Agreement by Parent and
Sub) constitutes a valid and binding obligation of the Company enforceable
against the Company in accordance with its terms, except to the extent
enforceability may be limited by bankruptcy, insolvency, reorganization,
moratorium, fraudulent transfer or other similar laws of general applicability
relating to or affecting the enforcement of creditors' rights and by the effect
of general principles of equity (regardless of whether enforceability is
considered in a proceeding in equity or at law). Except as set forth in Section
3.3 of the disclosure statement of the Company dated as of the date hereof,
previously delivered to Parent (the "Company Disclosure Schedule"), the
execution and delivery of this Agreement do not, and the consummation of the
transactions contemplated hereby and compliance with the provisions hereof will
not, conflict with, or result in any violation of, or default (with or without
notice or lapse of time, or both) under, or give rise to a right of
termination, cancellation or acceleration of any obligation or to the loss of a
material benefit under, or result in the creation of any lien, security
interest, charge or encumbrance upon any of the properties or assets of the
Company or any of its Significant Subsidiaries under, any provision of (i) the
Restated Certificate of Incorporation or By-laws of the Company (true and
complete copies of which as of the date hereof have been delivered to Parent)
or any provision of the comparable charter or organization documents of any of
its Significant Subsidiaries, (ii) any loan or credit agreement, note, bond,
mortgage, indenture, lease or other agreement, instrument, permit, concession,
franchise or license applicable to the Company or any of its Significant
Subsidiaries or (iii) any judgment, order, decree, statute, law, ordinance,
rule or regulation applicable to the Company or any of its Significant
Subsidiaries or any of their respective properties or assets, other than, in
the case of clauses (ii) or (iii), any such conflicts, violations, defaults,
rights, liens, security interests, charges or encumbrances that, individually
or in the aggregate, would not have a Material Adverse Effect on the Company,
materially impair the ability of the Company to perform its obligations
hereunder or prevent the consummation of any of the transactions contemplated
hereby. No filing or registration with, or authorization, consent or approval
of, any Governmental Entity is required by or with respect to the Company or
any of its Significant Subsidiaries in connection with the execution and
delivery of this Agreement by the Company or the consummation by the Company of
the transactions contemplated hereby, except for (i) in connection, or in
compliance, with the provisions of the Exchange Act, (ii) the filing of the
Certificate of Merger with the Secretary of State of the State of Delaware and
appropriate documents with the relevant authorities of other states in which
the Company or any of its Significant Subsidiaries is qualified to do business,
(iii) such filings and consents as may be required under any environmental,
health or safety law or regulation pertaining to any notification, disclosure
or required approval triggered by the Merger or the transactions contemplated
by this Agreement, (iv) such filings as may be required in connection with
applicable taxes, (v) such other consents, approvals, orders, authorizations,
registrations, declarations and filings as may be required under the
corporation, takeover or
 
                                      I-17
<PAGE>
 
"Blue Sky" laws of various states, (vi) such filings and approvals as may be
required under the Improvements Act, and (vii) such other consents, approvals,
orders, authorizations, registrations, declarations and filings the failure of
which to be obtained or made would not, individually or in the aggregate, have
a Material Adverse Effect on the Company, materially impair the ability of the
Company to perform its obligations hereunder or prevent the consummation of any
of the transactions contemplated hereby.
 
  Section 3.4 SEC Documents. The Company has filed all required documents with
the SEC since January 1, 1993 (the "Company SEC Documents"). As of their
respective dates, the Company SEC Documents complied in all material respects
with the requirements of the Securities Act or the Exchange Act, as the case
may be, and none of the Company SEC Documents contained any untrue statement of
a material fact or omitted to state a material fact required to be stated
therein or necessary in order to make the statements therein, in light of the
circumstances under which they were made, not misleading. The financial
statements of the Company included in the Company SEC Documents comply as to
form in all material respects with applicable accounting requirements and the
published rules and regulations of the SEC with respect thereto, have been
prepared in accordance with generally accepted accounting principles (except,
in the case of unaudited statements, as permitted by Form 10-Q of the SEC)
applied on a consistent basis during the periods involved (except as may be
indicated therein or in the notes thereto) and fairly present the consolidated
financial position of the Company and its consolidated Subsidiaries as at the
dates thereof and the consolidated results of their operations and changes in
financial position for the periods then ended (subject, in the case of
unaudited statements, to normal year-end audit adjustments and to any other
adjustments described therein). There is no liability or obligation of any
kind, whether accrued, absolute, fixed or contingent, of the Company or any
Subsidiary of the Company of which the executive officers of the Company have
knowledge and which is required by generally accepted accounting principles to
be reflected or reserved against or otherwise disclosed in the most recent
financial statements of the Company included in the Company SEC Documents which
is not so reflected or reserved against that individually or in the aggregate
would have a Material Adverse Effect on the Company.
 
  Section 3.5 Engineering Reports. All information supplied to Netherland,
Sewell & Associates, Inc. ("NSA") by or on behalf of the Company and its
Subsidiaries that was material to such firm's preparation of its oil and gas
reserve engineering report dated as of December 31, 1994 (the "Company
Engineering Report") regarding the Oil and Gas Interests of Plains Petroleum
Operating Company, a wholly-owned subsidiary of the Company ("PPOC"), was (at
the time supplied or as modified or amended prior to the issuance of the
Company Engineering Report) true and correct in all material respects. Except
for changes in classification or values of oil and gas reserve or property
interests that occurred in the ordinary course of business since December 31,
1994, and except for changes (including changes in commodity prices) generally
affecting the oil and gas industry on a nationwide basis, there has been no
Material Adverse Change in respect of the Company regarding the matters
addressed in the Company Engineering Report. All of the Oil and Gas Interests
of the Company and its Subsidiaries are held by PPOC, except the gathering,
transportation and automation equipment held by Plains Petroleum Gathering
Company, a wholly-owned subsidiary of PPOC ("PPGC").
 
  Section 3.6 Oil and Gas Reserve Information. (a) None of the wells included
in the Oil and Gas Interests of PPOC has been overproduced such that it is
subject or liable to being shut-in or to any other overproduction penalty,
except where any such overproduction would not have a Material Adverse Effect
on the Company.
 
  (b) There have been no changes proposed in the production allowables for any
wells included in the Oil and Gas Interests of PPOC that would have a Material
Adverse Effect on the Company.
 
  (c) All wells included in the Oil and Gas Interests of PPOC have been drilled
and (if completed) completed, operated, and produced in accordance with good
oil and gas field practices and in compliance in all material respects with
applicable oil and gas leases and applicable laws, rules, and regulations,
except where any failure or violation would not have a Material Adverse Effect
on the Company.
 
                                      I-18
<PAGE>
 
  (d) Neither the Company nor its Significant Subsidiaries has agreed to or is
now obligated to abandon any well included in the Oil and Gas Interests of PPOC
that is not or will not be abandoned and reclaimed in accordance with the
applicable laws, rules, and regulations and good oil and gas industry
practices, except where any abandonment would not have a Material Adverse
Effect on the Company.
 
  (e) Proceeds from the sale of Hydrocarbons produced from the Oil and Gas
Interests of PPOC are being received by the Company or its Significant
Subsidiaries in a timely manner and are not being held by third parties in
suspense for any reason (except for amounts, individually or in the aggregate,
not in excess of $1,000,000 and held in suspense in the ordinary course of
business).
 
  (f) No person has any call on, option to purchase, or similar rights with
respect to the Oil and Gas Interests of PPOC or PPGC or to the production
attributable thereto, and upon consummation of the transactions contemplated by
this Agreement, the Company or its Significant Subsidiaries will have the right
to market production from the Oil and Gas Interests of PPOC on terms no less
favorable than the terms upon which such company is currently marketing such
production, except where any call or option would not have a Material Adverse
Effect on the Company.
 
  Section 3.7 Registration Statement and Proxy Statement. None of the
information supplied or to be supplied by the Company for inclusion or
incorporation by reference in the Registration Statement or the Proxy Statement
will (i) in the case of the Registration Statement, at the time it becomes
effective and at the Effective Time, contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or
necessary in order to make the statements therein not misleading or (ii) in the
case of the Proxy Statement, at the time of the mailing of the Proxy Statement
and at the time of the Stockholder Meetings, contain any untrue statement of a
material fact or omit to state any material fact required to be stated therein
or necessary in order to make the statements therein, in the light of the
circumstances under which they are made, not misleading. If at any time prior
to the Effective Time any event with respect to the Company, its officers and
directors or any of its Subsidiaries should occur which is required to be
described in an amendment of, or a supplement to, the Proxy Statement or the
Registration Statement, such event shall be so described, and such amendment or
supplement shall be promptly filed with the SEC and, as required by law,
disseminated to the stockholders of the Company and Parent. The Registration
Statement will comply (with respect to the Company) as to form in all material
respects with the provisions of the Securities Act, and the Proxy Statement
will comply (with respect to the Company) as to form in all material respects
with the provisions of the Exchange Act.
 
  Section 3.8 Absence of Material Adverse Change. Except as disclosed in the
Company SEC Documents filed with the SEC prior to the date hereof, there has
not been any Material Adverse Change with respect to the Company (other than
changes in oil and gas generally accepted accounting principles or
interpretations thereof that affect the oil and gas industry generally or
changes in general economic conditions that affect the oil and gas industry on
a nationwide basis).
 
  Section 3.9 Pooling of Interests; Reorganization. To the knowledge of the
Company, neither it nor any of its Subsidiaries has (i) taken any action or
failed to take any action which action or failure to take action would
jeopardize the treatment of Sub's combination with the Company in the Merger as
a pooling of interests for accounting purposes or (ii) taken any action or
failed to take any action which action or failure to take action would
jeopardize the qualification of the Merger as a reorganization within the
meaning of Section 368(a) of the Code. Without limiting the foregoing: (i) to
the knowledge of the executive officers of the Company, there is no plan or
intention on the part of the holders of Company Common Stock to sell, exchange,
or otherwise dispose of a number of shares of Parent Common Stock that would
cause paragraph 2 of Section 7.03 of Rev. Proc. 77-37 (as amplified) not to be
true as applied to the Merger, and the only Company stockholders beneficially
owning more than 5% of the outstanding Company Common Stock are as set forth in
the Company's Annual Report on Form 10-K for the year ended December 31, 1994,
(ii) as of the Effective Time and immediately following the Merger, the
Surviving Corporation will hold "substantially all" of the Company's properties
within the meaning of Section 368(a)(2)(E) of the Code and Rev. Proc. 77-37
 
                                      I-19
<PAGE>
 
(as amplified), (iii) there is no intercorporate indebtedness between the
Company and Parent, (iv) immediately following the Merger, the Surviving
Corporation will be wholly owned directly by Parent, and the Surviving
Corporation will not have outstanding any type of right or obligation pursuant
to which any person could acquire capital stock of the Surviving Corporation,
and (v) the Company has no plan or intention for the Surviving Corporation to
issue additional shares of its capital stock following the Merger.
 
  Section 3.10 Taxes. Except as otherwise set forth in Section 3.10 of the
Company Disclosure Schedule, (i) the Company and each Significant Subsidiary
has filed all material Tax Returns required to have been filed on or before the
date hereof; (ii) all Taxes shown to be due on the Tax Returns referred in
clause (i) have been timely paid or extensions have been duly obtained or such
Taxes have been adequately provided for or are being timely and properly
contested; (iii) neither the Company nor any Significant Subsidiary has waived
any statute of limitations in respect of Taxes of the Company or such
Subsidiary; (iv) the Tax Returns referred to in clause (i) relating to federal
and state income Taxes have been examined by the Internal Revenue Service or
the appropriate state taxing authority or the period for assessment of the
Taxes in respect of which such Tax Returns were required to be filed has
expired; (v) no issues that have been raised in writing by the relevant taxing
authority in connection with the examination of the Tax Returns referred to in
clause (i) are currently pending; (vi) all deficiencies asserted or assessments
made as a result of any examination of the Tax Returns referred to in clause
(i) by a taxing authority have been paid in full or adequately provided for or
are being timely and properly contested; and (vii) neither the Company nor any
Significant Subsidiary of the Company is a party to an income Tax allocation or
sharing agreement with respect to a group of corporations filing Tax Returns on
a combined, consolidated or unitary basis.
 
  Section 3.11 Title to Property. The Company or its Subsidiaries has good and,
with respect to real property, marketable title to all of the material assets
reflected on the consolidated financial statements of the Company included in
the Company SEC Documents as being owned by it or its Subsidiaries and all of
the material assets thereafter acquired by it or its Subsidiaries (except to
the extent that such assets have thereafter been disposed of in the ordinary
course of business consistent with past practice), subject to no Liens, except
for (i) Liens for taxes not yet delinquent or the validity of which is being
contested in good faith and (ii) any Liens arising by operation of law securing
obligations not yet overdue. Notwithstanding the foregoing, title to the Oil
and Gas Interests of the Company and its Subsidiaries is of the type
customarily acceptable to prudent investors in Oil and Gas Interests in the
area where such Oil and Gas Interests of the Company and its Subsidiaries are
located.
 
  Section 3.12 Employee Benefit Plans. With respect to all the employee benefit
plans, programs and arrangements maintained for the benefit of any current or
former employee, officer or director of the Company or any Subsidiary of the
Company (collectively, the "Company Plans"), except as set forth in the Company
SEC Documents and except as would not, individually or in the aggregate, have a
Material Adverse Effect on the Company: (i) none of the Company Plans is a
multiemployer plan within the meaning of ERISA; (ii) none of the Company Plans
promises or provides retiree medical or life insurance benefits to any person,
except as otherwise required by law in the applicable jurisdiction and, outside
of the United States, in accordance with local custom and practice; (iii) each
Company Plan intended to be qualified under Section 401(a) of the Code has
received a favorable determination letter from the Internal Revenue Service
that it is so qualified and nothing has occurred since the date of such letter
that could reasonably be expected to affect the qualified status of such
Company Plan; (iv) each Company Plan has been operated in all respects in
accordance with its terms and the requirements of applicable law; (v) neither
the Company nor any Subsidiary of the Company has incurred any direct or
indirect liability under, arising out of or by operation of Title IV of ERISA
in connection with the termination of, or withdrawal from, any Company Plan or
other retirement plan or arrangement, and no fact or event exists that could
reasonably be expected to give rise to any such liability; and (vi) the Company
and its Subsidiaries have not incurred any liability under, and have complied
in all respects with, the Worker Adjustment Retraining Notification Act, and no
fact or event exists that could give rise to liability under such Act. Except
as set forth in the Company SEC Documents, the aggregate accumulated benefit
obligations of each Company Plan subject to Title IV of ERISA (as of the date
of the
 
                                      I-20
<PAGE>
 
most recent actuarial valuation prepared for such Company Plan) do not exceed
the fair market value of the assets of such Company Plan (as of the date of
such valuation).
 
  Section 3.13 Labor Matters. (a) Neither the Company nor any of its
Significant Subsidiaries is party to any collective bargaining agreement or
other material contract or agreement with any labor organization or other
representative of employees nor is any such contract being negotiated; (b)
there is no material unfair labor practice charge or complaint pending nor, to
the knowledge of the executive officers of the Company, threatened, with regard
to employees of the Company or any Significant Subsidiary; (c) there is no
labor strike, material slowdown, material work stoppage or other material labor
controversy in effect, or, to the knowledge of the executive officers of the
Company, threatened against the Company or any of its Significant Subsidiaries;
(d) as of the date hereof, no representation question exists, nor to the
knowledge of the executive officers of the Company are there any campaigns
being conducted to solicit cards from the employees of the Company or any
Significant Subsidiary of the Company to authorize representation by a labor
organization; (e) neither the Company nor any Significant Subsidiary of the
Company is party to, or is otherwise bound by, any consent decree with any
governmental authority relating to employees or employment practices of the
Company or any Significant Subsidiary of the Company; and (f) the Company and
each Significant Subsidiary of the Company are in compliance with all
applicable agreements, contracts and policies relating to employment,
employment practices, wages, hours and terms and conditions of employment of
the employees, except where the failure to be in compliance with each such
agreement, contract and policy would not, either singly or in the aggregate,
have a Material Adverse Effect on the Company.
 
  Section 3.14 Environmental Matters. Except to the extent that the inaccuracy
of any of the following, individually or in the aggregate, would not have a
Material Adverse Effect on the Company, to the knowledge of the executive
officers of the Company:
 
    (i) the Company and its Subsidiaries hold, and are in compliance with and
  have been in compliance with for the last two years, all Environmental
  Permits, and are otherwise in substantial compliance and have been in
  substantial compliance for the last two years with, all applicable
  Environmental Laws and there is no condition that is reasonably likely to
  prevent or materially interfere prior to the Effective Time with compliance
  by the Company and its Subsidiaries with Environmental Laws;
 
    (ii) no modification, revocation, reissuance, alteration, transfer or
  amendment of any Environmental Permit, or any review by, or approval of,
  any third party of any Environmental Permit is required in connection with
  the execution or delivery of this Agreement or the consummation by the
  Company of the transactions contemplated hereby or the operation of the
  business of the Company or any of its Subsidiaries on the date of the
  Closing;
 
    (iii) neither the Company nor any of its Subsidiaries has received any
  Environmental Claim, nor has any Environmental Claim been threatened
  against the Company or any of its Subsidiaries;
 
    (iv) neither the Company nor any of its Subsidiaries has entered into,
  agreed to or is subject to any outstanding judgment, decree, order or
  consent arrangement with any governmental authority under any Environmental
  Laws, including without limitation those relating to compliance with any
  Environmental Laws or to the investigation, cleanup, remediation or removal
  of Hazardous Materials;
 
    (v) there are no circumstances that are reasonably likely to give rise to
  liability under any agreements with any person pursuant to which the
  Company or any Subsidiary of the Company would be required to defend,
  indemnify, hold harmless, or otherwise be responsible for any violation by
  or other liability or expense of such person, or alleged violation by or
  other liability or expense of such person, arising out of any Environmental
  Law; and
 
    (vi) there are no other circumstances or conditions that are reasonably
  likely to give rise to liability of the Company or any of its Subsidiaries
  under any Environmental Laws.
 
  Section 3.15 Litigation. Except as set forth on Schedule 3.15 of the Company
Disclosure Schedule and except as disclosed prior to the date hereof in the
Company SEC Documents, there is no suit, action,
 
                                      I-21
<PAGE>
 
investigation or proceeding pending or, to the knowledge of the executive
officers of the Company, threatened against the Company or any of its
Subsidiaries at law or in equity before or by any federal, state, municipal or
other governmental department, commission, board, bureau, agency or
instrumentality, domestic or foreign, or before any arbitrator of any kind,
that would have a Material Adverse Effect on the Company or, with respect to
such matters that are pending or threatened as of the date hereof, materially
impair the ability of the Company to perform its obligations hereunder or to
consummate the transactions contemplated hereby, and there is no judgment,
decree, injunction, rule or order of any court, governmental department,
commission, board, bureau, agency, instrumentality or arbitrator to which the
Company or any of its Subsidiaries is subject that would have a Material
Adverse Effect on the Company or, with respect to such items that are
outstanding and applicable as of the date hereof, materially impair the ability
of the Company to perform its obligations hereunder or to consummate the
transactions contemplated hereby.
 
  Section 3.16 Governmental Licenses and Permits; Compliance with Law. Except
as disclosed prior to the date hereof in the Company SEC Documents, since
December 31, 1994, neither the Company nor any of its Significant Subsidiaries
has received notice of any revocation or modification of any federal, state,
local or foreign governmental license, certification, tariff, permit,
authorization or approval, the revocation or modification of which would have a
Material Adverse Effect on the Company. To the knowledge of the executive
officers of the Company, the conduct of the business of each of the Company and
its Subsidiaries complies with all statutes, laws, regulations, ordinances,
rules, judgments, orders, decrees or arbitration awards applicable thereto,
except for violations or failures to comply, if any, that, individually or in
the aggregate, would not have a Material Adverse Effect on the Company.
 
  Section 3.17 Required Vote of the Company Stockholders. The affirmative vote
of the holders of not less than a majority of the outstanding shares of the
Company Common Stock is required to adopt this Agreement and approve the Merger
and the other transactions contemplated hereby. No other vote of the
stockholders of the Company is required by law, the Restated Certificate of
Incorporation or By-laws of the Company or otherwise to adopt this Agreement
and approve the Merger and the other transactions contemplated hereby.
 
  Section 3.18 Company Action. The Board of Directors of the Company (at a
meeting duly called and held) unanimously (a) determined that the Merger is
fair to and advisable and in the best interests of the Company and its
stockholders, (b) approved this Agreement and the Merger in accordance with the
DGCL, (c) resolved to recommend approval and adoption of this Agreement and
Merger by the Company's stockholders and (d) directed that this Agreement be
submitted to the Company's stockholders. As a result of the approvals and
determinations described in clauses (a) and (b) above, the provisions of
Article Eleventh of the Restated Certificate of Incorporation of the Company
will not be applicable to the Merger as a "Business Transaction" (as defined in
such Restated Certificate of Incorporation).
 
  Section 3.19 Section 203 of the DGCL Not Applicable. The Board of Directors
of the Company has approved the Merger and this Agreement and such approval is
sufficient to render inapplicable to the Merger and the other transactions
contemplated hereby the restrictions contained in Section 203 of the DGCL.
 
  Section 3.20 Amendment to Company Rights Agreement. (a) The Board of
Directors of the Company has taken all necessary action to amend the Rights
Agreement so that none of the execution and delivery of this Agreement, the
conversion of shares of the Company Common Stock (and associated Rights) into
shares of Parent Common Stock and cash in lieu of fractional shares in
accordance with Article I of this Agreement, and the consummation of the Merger
or any other transaction contemplated hereby will cause (i) the Rights issued
pursuant to the Rights Agreement to become exercisable under the Rights
Agreement or (ii) Parent or any of Parent's direct or indirect Subsidiaries to
be deemed an "Acquiring Person" (as defined in the Rights Agreement). The
Company has delivered to Parent a true, correct and complete copy of the Rights
Agreement to Parent prior to the date hereof and has delivered a true, correct
and complete copy of the aforesaid amendment executed by the Company, a
counterpart of which will be promptly delivered to the Rights Agent for its
counter-execution.
 
                                      I-22
<PAGE>
 
  (b) The "Distribution Date" (as defined in the Rights Agreement) has not
occurred and will not occur as a result of the Merger.
 
  Section 3.21 Opinion of Financial Advisor. On the date hereof, the Company
has received the written opinion of Goldman, Sachs & Co. to the effect that the
Exchange Ratio is fair to the holders of the Company Common Stock.
 
  Section 3.22 Brokers. No broker, investment banker or other person, other
than Goldman, Sachs & Co. and Batchelder & Partners, Inc., the fees and
expenses of each which will be paid by the Company, is entitled to any
broker's, finder's or other similar fee or commission in connection with the
transactions contemplated by this Agreement based upon arrangements made by or
on behalf of the Company. The Company has previously delivered to Parent a
true, correct and complete copy of any engagement or fee agreement between the
Company and its Subsidiaries, on the one hand, and Goldman, Sachs & Co. or
Batchelder & Partners, Inc., on the other.
 
                                   ARTICLE IV
 
                  Representations and Warranties Regarding Sub
 
  Parent and Sub jointly and severally represent and warrant to the Company as
follows:
 
  Section 4.1 Organization and Standing. Sub is a corporation duly
incorporated, validly existing and in good standing under the laws of the State
of Delaware. Sub was organized solely for the purpose of acquiring the Company
and engaging in the transactions contemplated by this Agreement and has not
engaged in any business since it was incorporated which is not in connection
with the Merger and this Agreement.
 
  Section 4.2 Capital Structure. The authorized capital stock of Sub consists
of 1,000 shares of common stock, par value $.01 per share, all of which are
validly issued and outstanding, fully paid and nonassessable and are owned by
Parent free and clear of all liens, claims and encumbrances.
 
  Section 4.3 Authority; Non-Contravention. Sub has the requisite power and
authority to enter into this Agreement and to consummate the transactions
contemplated hereby. The execution and delivery of this Agreement, the
performance by Sub of its obligations hereunder and the consummation of the
transactions contemplated hereby have been duly authorized by its Board of
Directors and Parent as its sole stockholder, and, except for the corporate
filings required by state law, no other corporate proceedings on the part of
Sub are necessary to authorize this Agreement and the transactions contemplated
hereby. This Agreement has been duly and validly executed and delivered by Sub
and (assuming the due authorization, execution and delivery hereof by the
Company) constitutes a valid and binding obligation of Sub enforceable against
Sub in accordance with its terms, except to the extent enforceability may be
limited by bankruptcy, insolvency, reorganization, moratorium, fraudulent
transfer or other similar laws of general applicability relating to or
affecting the enforcement of creditors' rights and by the effect of general
principles of equity (regardless of whether enforceability is considered in a
proceeding in equity or at law). The execution and delivery of this Agreement
do not, and the consummation of the transactions contemplated hereby and
compliance with the provisions hereof will not, conflict with, or result in any
violation of, or default (with or without notice or lapse of time, or both)
under, or give rise to a right of termination, cancellation or acceleration of
any obligation or to the loss of a material benefit under, or result in the
creation of any lien, security interest, charge or encumbrance upon any of the
properties or assets of Sub under, any provision of (i) the Certificate of
Incorporation or By-laws (true and complete copies of which as of the date
hereof have been delivered to the Company) of Sub, (ii) any loan or credit
agreement, note, bond, mortgage, indenture, lease or other agreement,
instrument, permit, concession, franchise or license applicable to Sub or (iii)
any judgment, order, decree, statute, law, ordinance, rule or regulation
applicable to Sub or any of its properties or assets, other than, in the case
of clauses (ii) or (iii), any such conflicts, violations, defaults, rights,
liens, security interests,
 
                                      I-23
<PAGE>
 
charges or encumbrances that, individually or in the aggregate, would not have
a Material Adverse Effect on Sub, materially impair the ability of Sub to
perform its obligations hereunder or prevent the consummation of any of the
transactions contemplated hereby.
 
                                   ARTICLE V
 
                   Covenants Relating to Conduct of Business
 
  Section 5.1 Conduct of Business Pending the Merger.
 
  (a) Actions. During the period from the date of this Agreement through the
Effective Time, unless Parent or the Company, as the case may be, shall consent
thereto in writing (which consent will not be unreasonably withheld), each of
the Company and Parent shall, and each shall cause its respective Subsidiaries
to, in all material respects carry on its respective businesses in the ordinary
course and consistent with past practice and, to the extent consistent
therewith and with the terms of this Agreement, use all reasonable efforts to
preserve intact its current business organizations, keep available the services
of its current officers and employees and preserve its relationships with
customers, suppliers and others having business dealings with it to the end
that its goodwill and ongoing businesses shall be unimpaired at the Effective
Time. Without limiting the generality of the foregoing, prior to the Effective
Time, except as otherwise expressly contemplated by this Agreement (including,
but not limited to, Section 5.2) or Section 5.1 of the Company Disclosure
Schedule, each of the Company and Parent shall not, and each shall cause its
respective Subsidiaries not to, without the prior written consent of the other
parties to this Agreement:
 
    (i) (x) declare, set aside or pay any dividends on, or make any other
  actual, constructive or deemed distributions in respect of, any of its
  respective capital stock, or otherwise make any payments to its respective
  stockholders in their capacity as such, other than (1) ordinary quarterly
  dividends by the Company consistent with past practice in an amount not in
  excess of $.06 per share with respect to Company Common Stock, (2)
  dividends declared by the Company prior to the date of this Agreement, and
  (3) dividends payable to the Company declared by any of the Company's
  Subsidiaries or to Parent declared by any of Parent's Subsidiaries, (y)
  split, combine or reclassify any of its capital stock or issue or authorize
  the issuance of any other securities in respect of, in lieu of or in
  substitution for shares of its capital stock, or (z) purchase, redeem or
  otherwise acquire any shares of capital stock of each of the Company or
  Parent, or any of its respective Subsidiaries or any other securities
  thereof or any rights, warrants or options to acquire any such shares or
  other securities, except in connection with the terms of their respective
  stock option plans in existence on February 15, 1995, and in the case of
  the Company, except in connection with the terms of its 401(k) Plan and the
  Company Profit Sharing Plan;
 
    (ii) issue, deliver, sell, pledge, dispose of or otherwise encumber any
  shares of its or its Subsidiaries' capital stock, any other voting
  securities or equity equivalent or any securities convertible into, or any
  rights, warrants or options to acquire, any such shares, voting securities
  or convertible securities or equity equivalent (other than, in the case of
  the Company or Parent, the issuance of Company Common Stock or Parent
  Common Stock, as the case may be, during the period from the date of this
  Agreement through the Effective Time (x) upon the exercise of Company Stock
  Options or Parent stock options, as the case may be, outstanding on the
  date of this Agreement in accordance with their current terms or (y) in
  accordance with the terms, existing at the date of this Agreement, of the
  401(k) Plan and the Company Profit Sharing Plan in the case of the Company,
  and the Barrett Resources Corporation 1990 Stock Option Plan and the
  Barrett Resources Corporation 1994 Stock Option Plan in the case of
  Parent);
 
    (iii) amend its Certificate of Incorporation or amend in any material
  respects its By-laws, other than the Charter Amendment and an amendment to
  Parent's By-laws to satisfy the condition contained in Section 7.2(e);
 
    (iv) acquire, merge or consolidate with, or purchase a portion of the
  assets of or equity in, any corporation, partnership, association or other
  business organization or division thereof or otherwise acquire any assets,
  in each case that involves a transaction exceeding $50,000 in the
  aggregate, or engage
 
                                      I-24
<PAGE>
 
  in any negotiations with any person or entity concerning any such
  transaction; provided, however, that the Company and Parent may acquire Oil
  and Gas Interests in the ordinary course of business consistent with past
  practice;
 
    (v) except in the ordinary course of business, sell, lease or otherwise
  dispose of or agree to sell, lease or otherwise dispose of, any business or
  line of business or any of its assets, in each case that are material,
  individually or in the aggregate, to the Company and its Subsidiaries taken
  as a whole, or to Parent and its Subsidiaries taken as a whole,
  respectively;
 
    (vi) make any capital expenditures, except in the ordinary course of
  business;
 
    (vii) (A) pay, discharge, or satisfy any material claims, liabilities, or
  obligations (absolute, accrued, asserted or unasserted, contingent or
  otherwise), except for the payment, discharge or satisfaction of its
  liabilities or its obligations in the ordinary course of business or in
  accordance with their terms as in effect on the date hereof; (B) adopt a
  plan of complete or partial liquidation or resolutions providing for or
  authorizing such a liquidation or a dissolution, restructuring,
  recapitalization or reorganization; (C) enter into any collective
  bargaining agreement, successor collective bargaining agreement or amended
  collective bargaining agreement; (D) change any accounting principle used
  by it, except for such changes required to be implemented prior to the
  Effective Time pursuant to generally accepted accounting principles or
  rules of the SEC; or (E) settle or compromise any litigation brought
  against it, other than settlements or compromises of any litigation where
  the amount paid in settlement or compromise (including without limitation
  the cost to Parent and its Subsidiaries or the Company and its
  Subsidiaries, as the case may be, of complying with any provision of such
  settlement or compromise other than cash payments) does not exceed
  $200,000, exclusive of amounts covered by insurance;
 
    (viii) (A) enter into any new, or amend any existing, severance agreement
  or arrangement, deferred compensation arrangement or employment agreement
  with any officer, director or employee, except that, subject to Section
  6.13(e), Parent and the Company may hire additional employees to the extent
  deemed by their respective managements to be in the best interests of
  Parent or the Company, as the case may be, provided, that neither the
  Company nor Parent may enter into any employment or severance agreement or
  any deferred compensation arrangement with any such additional employees,
  (B) adopt any new, or amend any existing, incentive, retirement or welfare
  benefit arrangements, plans or programs for the benefit of current, former
  or retired employees (other than amendments required by law or to maintain
  the tax qualified status of such plans under the Code), or (C) grant any
  increases in employee compensation, other than in the ordinary course or
  pursuant to promotions, in each case consistent with past practice (which
  shall include normal individual periodic performance reviews and related
  compensation and benefit increases and bonus payments and awarded under
  existing plans and forgiveness of employee indebtedness incurred in
  connection with relocation loans made under existing policies);
 
    (ix) except in the ordinary course of business consistent with past
  practice, (y) incur any indebtedness for borrowed money or guarantee any
  such indebtedness or issue or sell any debt securities or guarantee any
  debt securities of others or (z) make any loans, advances or capital
  contributions to, or investments in, any other person, other than to the
  Company or any wholly-owned Subsidiary of the Company or to Parent or any
  wholly-owned Subsidiary of Parent, respectively; or
 
    (x) authorize or enter into any agreement to do any of the foregoing.
 
  (b) Advice of Changes. Each of the Company and Parent shall promptly advise
the other such party orally and in writing of any change or event which would
have a Material Adverse Effect on the Company or Parent, respectively.
 
  Section 5.2 No Solicitation. From and after the date hereof, the Company will
not, and will cause its Subsidiaries and its officers, directors, employees,
agents and other representatives and those of any of its Subsidiaries not to,
directly or indirectly, solicit or initiate any takeover proposal or offer for
the Company, and not to solicit or initiate, directly or indirectly,
discussions, negotiations, considerations or inquiries
 
                                      I-25
<PAGE>
 
concerning a takeover proposal or offer for the Company, from any person, or
engage in discussions or negotiations relating thereto, or provide to any other
person any information or data relating to the Company or its Subsidiaries for
the purpose of, or have any substantive discussions with, any person relating
to, or otherwise cooperate with or assist or participate in, or facilitate, any
takeover proposal or offer or any inquiry or proposal which would reasonably be
expected to lead to any effort or attempt by any other person to seek to effect
a takeover proposal or offer, or agree to or endorse any such inquiry, takeover
proposal or offer; provided, however, that (i) the Company may engage in
discussions or negotiations with a third party who, without the Company taking
any action which is proscribed as provided above in this Section 5.2, seeks to
initiate such discussions or negotiations or may furnish such third party
information concerning the Company and its business, properties or assets
(provided that such third party executes a confidentiality agreement with the
Company) and (ii) the Company's Board of Directors may take and disclose to the
Company's stockholders a position contemplated by Rules 14d-9 and 14e-2(a)
promulgated under the Exchange Act, but in each case referred to in the
foregoing clauses (i) and (ii) only to the extent that a majority of the Board
of Directors of the Company shall conclude in good faith, after consultation
with and based upon the written advice of Sidley & Austin or Richards, Layton &
Finger (which advice need not constitute an opinion), that such action is
necessary in order for the Board of Directors of the Company not to breach its
fiduciary obligations under applicable law. The Company will promptly (but in
no case later than 24 hours) notify Parent of any inquiry, takeover proposal or
offer for the Company, including the material terms and conditions thereof, but
shall not be required to indicate the identity of the person or group making
such takeover proposal or offer. It is agreed and understood that any
termination of this Agreement shall be solely pursuant to Section 8.1 and that,
prior to any such termination, the Company shall not enter into any written
agreement with any person that provides for, or in any way facilitates, a
takeover proposal or offer, other than a confidentiality agreement. Except as
permitted by this Section 5.2, the Company and its Subsidiaries and their
officers, directors, employees, agents and other representatives will
immediately cease the Company's or its Subsidiaries' existing discussions,
negotiations and other activities with any parties (other than Parent) relating
to any possible takeover proposal or offer. As used in this Agreement,
"takeover proposal" or "offer" shall mean any proposal or offer (other than a
proposal or offer by Parent or any of its affiliates) for a tender or exchange
offer, a merger, consolidation or other business combination involving the
Company or any Subsidiary of the Company, or any proposal to acquire in any
manner a substantial equity interest in, or a substantial portion of the assets
of, the Company or any of its Subsidiaries. Without limiting the foregoing, it
is understood that any violation of the restrictions set forth in this Section
5.2 by any officer or director or authorized employee, agent or representative
of the Company or any of its Subsidiaries shall be deemed to be a breach of
this Section 5.2 by the Company.
 
  Section 5.3 Pooling of Interests; Reorganization. During the period from the
date of this Agreement through the Effective Time, unless the other parties
shall otherwise agree in writing, none of Parent, Sub, any other Subsidiary of
Parent, the Company nor any Subsidiary of the Company shall (a) knowingly take
or fail to take any action which action or failure to act would jeopardize the
treatment of Sub's combination with the Company as a pooling of interests for
accounting purposes or (b) knowingly take or fail to take any action which
action or failure to act would jeopardize qualification of the Merger as a
reorganization within the meaning of Section 368(a) of the Code.
 
  Section 5.4 Conduct of Business of Sub Pending the Merger. During the period
from the date of this Agreement through the Effective Time, Sub shall not
engage in any activities of any nature except as expressly provided in or
contemplated by this Agreement or incident thereto.
 
                                   ARTICLE VI
 
                             Additional Agreements
 
  Section 6.1 Stockholder Approval. (a) The Company shall promptly call a
meeting of its stockholders (the "Company Stockholder Meeting") for the purpose
of voting upon the Merger and shall use
 
                                      I-26
<PAGE>
 
its reasonable best efforts to obtain stockholder approval of the Merger. The
Company Stockholder Meeting shall be held as soon as practicable following the
date upon which the Registration Statement becomes effective, and the Company
will, through its Board of Directors (unless the Board of Directors shall
conclude in good faith, after consultation with and based upon the written
advice of Sidley & Austin or Richards, Layton & Finger (which advice need not
constitute an opinion), that not recommending the Merger, or withdrawing or
modifying any such recommendation, is necessary in order for the Board of
Directors not to breach its fiduciary obligations under applicable law),
recommend to its stockholders the approval of the Merger and not rescind its
declaration that the Merger is fair to and advisable and in the best interest
of the Company and its stockholders; provided, however, that any failure of the
Board of Directors of the Company to recommend the approval of the Merger, or
any withdrawal or modification of such a recommendation, shall not be deemed a
violation of Section 5.2.
 
  (b) Parent shall promptly call a meeting of its stockholders (the "Parent
Stockholder Meeting" and, together with the Company Stockholder Meeting, the
"Stockholder Meetings") for the purpose of voting upon the Charter Amendment
and the Share Issuance and shall use its reasonable best efforts to obtain
stockholder approval of such matters. Parent will, through its Board of
Directors (unless the Board of Directors shall conclude in good faith, after
consultation with and based upon the written advice of Simpson Thacher &
Bartlett (which advice need not constitute an opinion), that not recommending
the Charter Amendment and Share Issuance, or withdrawing or modifying any such
recommendation, is necessary in order for the Board of Directors not to breach
its fiduciary obligations under applicable law), recommend to its stockholders
the approval of the Charter Amendment and the Share Issuance and not rescind
its declaration that such transactions are fair to and advisable and in the
best interest of Parent and its stockholders. The Parent Stockholder Meeting
shall be on the date of the Company Stockholder Meeting or, if such date is not
practicable, on the closest date practicable.
 
  Section 6.2 Registration Statement and Proxy Statement. (a) Parent and the
Company shall prepare and file with the SEC as soon as practicable a proxy
statement for use at the Stockholder Meetings (the "Proxy Statement"), and
Parent shall prepare and file with the SEC as soon as practicable the
Registration Statement (including the Proxy Statement as a prospectus therein)
and shall use all reasonable efforts to have the Registration Statement
declared effective by the SEC as soon as practicable. Parent shall also take
any action required to be taken under state securities or "Blue Sky" laws in
connection with the issuance of the Parent Common Stock pursuant to the Merger
and the exercise of the Company Stock Options after the Effective Time. The
Company and Parent shall furnish each other all information concerning the
Company and the holders of Company Common Stock or Parent and the holders of
Parent Common Stock, as the case may be, required for use in the Registration
Statement and the Proxy Statement, and the Company and Parent each shall take
such other actions as the other may reasonably request in connection with the
preparation of such Registration Statement and the Proxy Statement and the
actions to be taken pursuant to this Section 6.2.
 
  Section 6.3 Access to Information. (a) The Company shall, and shall cause
each of its Subsidiaries to, afford to Parent, and to Parent's accountants,
counsel, financial advisers and other representatives, reasonable access and
permit them to make such inspections as they may reasonably require during the
period from the date of this Agreement through the Effective Time to all their
respective properties, books, contracts, commitments and records and, during
such period, the Company shall, and shall cause each of its Subsidiaries to,
furnish promptly to Parent (i) access to each report, schedule, registration
statement and other document filed by it during such period pursuant to the
requirements of federal or state laws and (ii) all other information concerning
the Company, its business, properties and personnel as Parent may reasonably
request. In no event shall the Company be required to supply to Parent, or to
Parent's accountants, counsel, financial advisors or other representatives, any
information relating to indications of interest from, or discussions with, any
other potential acquirors of the Company which were received or conducted prior
to the date hereof except to the extent necessary for use in the Registration
Statement. Except as required by law, Parent will hold, and will cause its
affiliates, associates and representatives to hold, any nonpublic
 
                                      I-27
<PAGE>
 
information in confidence until such time as such information otherwise becomes
publicly available and shall use its reasonable best efforts to ensure that
such affiliates, associates and representatives do not disclose such
information to others without the prior written consent of the Company. In the
event of termination of this Agreement for any reason, Parent shall promptly
return or destroy all nonpublic documents so obtained from the Company or any
of its Subsidiaries and any copies made of such documents for Parent. Parent
shall not, and shall cause its affiliates, associates and representatives not
to, use any nonpublic information regarding the Company and its Subsidiaries in
any way detrimental to the Company and its Subsidiaries.
 
  (b) Parent shall, and shall cause each of its Subsidiaries to, afford to the
Company, and to Company's accountants, counsel, financial advisers and other
representatives, reasonable access and permit them to make such inspections as
they may reasonably require during the period from the date of this Agreement
through the Effective Time to all their respective properties, books,
contracts, commitments and records and, during such period, Parent shall, and
shall cause each of its Subsidiaries to, furnish promptly to the Company
(i) access to each report, schedule, registration statement and other document
filed by it during such period pursuant to the requirements of federal or state
laws and (ii) all other information concerning Parent, its business, properties
and personnel as the Company may reasonably request. Except as required by law,
the Company will hold, and will cause its affiliates, associates and
representatives to hold, any nonpublic information in confidence until such
time as such information otherwise becomes publicly available and shall use its
reasonable best efforts to ensure that such affiliates, associates and
representatives do not disclose such information to others without the prior
written consent of Parent. In the event of termination of this Agreement for
any reason, the Company shall promptly return or destroy all nonpublic
documents so obtained from Parent or any of its Subsidiaries and any copies
made of such documents for the Company. The Company shall not, and shall cause
its affiliates, associates and representatives not to, use any nonpublic
information regarding Parent and it Subsidiaries in any way detrimental to
Parent and its Subsidiaries.
 
  (c) No investigation pursuant to this Section 6.3 shall affect any
representation or warranty in this Agreement of any party hereto or any
condition to the obligations of the parties hereto.
 
  Section 6.4 Compliance with the Securities Act; Pooling. Prior to the
Effective Time, the Company shall cause to be prepared and delivered to Parent
a list (reasonably satisfactory to counsel for Parent) identifying all persons
who, at the time of the Stockholder Meetings, may be deemed to be "affiliates"
of the Company as that term is used in paragraphs (c) and (d) of Rule 145 under
the Securities Act (the "Affiliates"). The Company shall use its reasonable
best efforts to cause each person who is identified as an Affiliate in such
list to deliver to Parent on or prior to the Effective Time a written
agreement, in the form previously approved by the parties hereto, that such
Affiliate will not sell, pledge, transfer or otherwise dispose of any shares of
Parent Common Stock issued to such possible Affiliate pursuant to the Merger,
except pursuant to an effective registration statement or in compliance with
Rule 145 or an exemption from the registration requirements of the Securities
Act and that such Affiliate will not sell or in any other way reduce such
Affiliate's risk relative to any shares of Parent Common Stock received in the
Merger (within the meaning of Section 201.01 of the SEC's Financial Reporting
Release No. 1), until such time as financial results (including combined sales
and net income) covering at least 30 days of post-Merger operations have been
published, except as permitted by Staff Accounting Bulletin No. 76 issued by
the SEC.
 
  Section 6.5 Stock Exchange Listing. Parent shall use its reasonable best
efforts to list on the NYSE, upon official notice of issuance, the shares of
Parent Common Stock to be issued in connection with the Merger and pursuant to
the Company Stock Options.
 
  Section 6.6 Fees and Expenses. (a) Whether or not the Merger is consummated,
except as provided in Section 6.6(b), all costs and expenses incurred in
connection with this Agreement and the transactions contemplated hereby shall
be paid by the party incurring such costs and expenses.
 
  (b) (i) Notwithstanding any provision in this Agreement to the contrary, if
Parent terminates this Agreement pursuant to Section 8.1(b)(i) or 8.1(e), then
the Company shall pay to Parent, within five business
 
                                      I-28
<PAGE>
 
days following such termination, an amount in cash equal to all out-of-pocket
expenses actually and reasonably incurred by Parent and its Subsidiaries in
connection with this Agreement and the transactions contemplated hereby. In
addition, if within nine months after such termination the Company enters into
an agreement with respect to a Third Party Acquisition of the Company (the
"Company Acquisition Agreement") or there shall have occurred, or the Board of
Directors shall have recommended to the stockholders of the Company or resolved
to do so, a Third Party Acquisition, then upon the earliest of such events, the
Company shall immediately pay to Parent an amount in cash equal to $8,000,000
less the amount paid by the Company to Parent pursuant to the immediately
preceding sentence in respect of Parent's expenses.
 
  (ii) Notwithstanding any provision in this Agreement to the contrary, if
Parent terminates this Agreement pursuant to Section 8.1(b)(ii) or the Company
terminates this Agreement pursuant to Section 8.1(c)(ii), and, in addition,
within nine months after such termination the Company enters into a Company
Acquisition Agreement or there shall have occurred, or the Board of Directors
shall have recommended to the stockholders of the Company or resolved to do so,
a Third Party Acquisition, then, upon the earliest of such events, the Company
shall immediately pay to Parent cash in the amount of $8,000,000.
 
  (iii) Notwithstanding any provision in this Agreement to the contrary, if
Parent terminates this Agreement pursuant to Section 8.1(f)(i), then the
Company shall immediately pay to Parent cash in the amount of $5,000,000. In
addition, if within nine months thereafter the Company enters into a Company
Acquisition Agreement or there shall have occurred, or the Board of Directors
shall have recommended to the stockholders of the Company or resolved to do so,
a Third Party Acquisition, then upon the earliest of such events, the Company
shall immediately pay to Parent cash in the amount of $3,000,000.
 
  (iv) Notwithstanding any provision in this Agreement to the contrary, if the
Company terminates this Agreement pursuant to Section 8.1(h) or Parent
terminates this Agreement pursuant to Sections 8.1(f)(ii) or 8.1(i), then the
Company shall immediately pay to Parent cash in the amount of $8,000,000.
 
  (v) The Company shall in no event be obligated to make payments under this
Section 6.6(b) exceeding, in the aggregate, $8,000,000.
 
  (c) For purposes of this Agreement, the term "Third Party Acquisition" means
the occurrence of any of the following events: (i) the acquisition of the
Company by merger, tender offer or otherwise, other than by Parent or any of
its affiliates, (ii) except as contemplated by clause (iii) of this Section
6.6(c), the acquisition of more than 20% of the outstanding shares of Company
Common Stock (measured after such issuance), or securities exercisable,
convertible or exchangeable into more than 20% of the outstanding shares of
Company Common Stock (assuming the exercise, conversion or exchange of such
securities), or any other securities which represent, or are exercisable,
convertible or exchangeable into securities which represent, more than 20% of
the voting power of the outstanding securities of the Company (assuming the
exercise, conversion or exchange of such securities) ordinarily (absent the
occurrence of any contingency) having the right to vote in the election of
directors of the Company, by any person other than Parent or its affiliates or
(iii) the issuance to any person (other than Parent or its affiliates) of more
than 30% of the outstanding shares of Company Common Stock (measured after such
issuance), or securities exercisable, convertible or exchangeable into more
than 30% of the outstanding shares of Company Common Stock (assuming the
exercise, conversion or exchange of such securities), or any other securities
which represent, or are exercisable, convertible or exchangeable into
securities which represent, more than 30% of the voting power of the
outstanding securities of the Company (assuming the exercise, conversion or
exchange of such securities) ordinarily (absent the occurrence of any
contingency) having the right to vote in the election of directors of the
Company, in connection with an acquisition by the Company of any other person
or entity.
 
  Section 6.7 Company Stock Options. No later than the Effective Time, each
option to purchase shares of Company Common Stock (a "Company Stock Option")
which is outstanding immediately prior to the Effective Time pursuant to the
Company's stock option plans (the "Stock Plans") shall become and
 
                                      I-29
<PAGE>
 
represent an option to purchase the number of shares of Parent Common Stock (a
"Substituted Option") (decreased to the nearest full share) determined by
multiplying (i) the number of shares of Company Common Stock subject to such
Company Stock Option immediately prior to the Effective Time by (ii) the
Exchange Ratio, at an exercise price per share of Parent Common Stock (rounded
down to the nearest whole cent) equal to the exercise price per share of
Company Common Stock immediately prior to the Effective Time divided by the
Exchange Ratio. Parent shall pay cash to holders of Company Stock Options in
lieu of issuing fractional shares of Parent Common Stock upon the exercise of
Company Stock Options for shares of Parent Common Stock. After the Effective
Time, except as provided above in this Section 6.7, each Substituted Option
shall be exercisable upon the same terms and conditions as were applicable
under the related Company Stock Option simultaneously with the Effective Time.
 
  Section 6.8 Reasonable Efforts. Upon the terms and subject to the conditions
set forth in this Agreement, each of the parties agrees to use all reasonable
efforts to take, or cause to be taken, all actions, and to do, or cause to be
done, and to assist and cooperate with the other parties in doing, all things
necessary, proper or advisable to consummate and make effective, in the most
expeditious manner practicable, the Merger and the other transactions
contemplated by this Agreement and the prompt satisfaction of the conditions
hereto, including (a) the obtaining of all necessary actions or non-actions,
waivers, consents and approvals from Governmental Entities and the making of
all necessary registrations and filings and the taking of all reasonable steps
as may be necessary to obtain an approval or waiver from, or to avoid an action
or proceeding by any Governmental Entity, including but not limited to any
filing under the Improvements Act, (b) the obtaining of all necessary consents,
approvals or waivers from third parties, (c) the defending of any lawsuits or
other legal proceedings, whether judicial or administrative, challenging this
Agreement or the consummation of the transactions contemplated hereby,
including seeking to have any stay or temporary restraining order entered by
any court or other Governmental Entity vacated or reversed, (d) the execution
and delivery of any additional instruments necessary to consummate the
transactions contemplated by this Agreement; provided, however, that neither of
the parties shall be under any obligation to take any action to the extent that
the Board of Directors of such party shall conclude in good faith, after
consultation with and based upon the written advice of Sidley & Austin or
Richards, Layton & Finger in the case of the Company, and Simpson Thacher &
Bartlett, in the case of Parent, (which advice in each case need not constitute
an opinion), that such action would cause a breach of that board of directors'
fiduciary obligations under applicable law, and (e) the obtaining of a written
agreement, concurrently with the execution of this Agreement or as soon as
practicable thereafter, from each of the individuals identified in Section 6.8
of the Parent Disclosure Schedule and Section 6.8 of the Company Disclosure
Schedule, to vote at the Stockholder Meetings the shares of Parent Common Stock
or Company Common Stock, as the case may be, beneficially owned by such
individuals in favor of this Agreement, the Merger and the transactions
contemplated hereby (in the case of the Company Stockholder Meeting), and this
Agreement, the Charter Amendment, the Share Issuance and the transactions
contemplated hereby (in the case of the Parent Stockholder Meeting).
Notwithstanding anything to the contrary in this Section 6.8, neither party
shall be required to agree to, nor shall either party without the prior consent
of the other party commit to, any divestiture transaction.
 
  Section 6.9 Public Announcements. Before issuing any press release or
otherwise making any public statements with respect to the transactions
contemplated by this Agreement, Parent and Sub, on the one hand, and the
Company, on the other hand, will consult with each other, and will undertake
reasonable efforts to agree upon the terms of such press release, and shall not
issue any such press release or make any such public statement prior to such
consultation, except as may be required by applicable law or by obligations
pursuant to any listing agreement with any national securities exchange.
 
  Section 6.10 Real Estate Transfer and Gains Tax. Parent and the Company agree
that either the Company or the Surviving Corporation will pay any real property
transfer or gains tax or similar tax, in each case attributable to the transfer
of the beneficial ownership of the Company's or its Subsidiaries' real
property, if any (collectively, the "Gains Taxes"), and any penalties or
interest with respect to the Gains Taxes, payable in connection with the
consummation of the Merger. The Company agrees to cooperate with Sub in the
filing
 
                                      I-30
<PAGE>
 
of any returns with respect to the Gains Taxes, including supplying in a timely
manner a complete list of all real property interests held by the Company or
its Subsidiaries and any information with respect to such property that is
reasonably necessary to complete such returns. The portion of the consideration
allocable to the real property of the Company and its Subsidiaries shall be
determined by Sub or Parent in its reasonable discretion. The stockholders of
the Company shall be deemed to have agreed to be bound by the allocation
established pursuant to this Section 6.10 in the preparation of any return with
respect to the Gains Taxes.
 
  Section 6.11 Indemnification; Directors and Officers Insurance. From and
after the Effective Time, Parent agrees to indemnify and hold harmless all past
and present officers and directors of the Company and of its Subsidiaries to
the full extent such persons may be indemnified by the Company pursuant to the
Company's Certificate of Incorporation and By-Laws for acts or omissions
occurring at or prior to the Effective Time and shall advance reasonable
litigation expenses incurred by such officers and directors in connection with
defending any action arising out of such acts or omissions. In addition, Parent
will provide, or cause the Surviving Corporation to provide, for a period of
not less than six years from the Effective Time, the Company's current
directors and officers with an insurance and indemnification policy that
provides coverage for events occurring through the Effective Time (the "D&O
Insurance") that is no less favorable than the existing policy or, if
substantially equivalent insurance coverage is unavailable, the best available
coverage; provided, however, that Parent and the Surviving Corporation shall
not be required to pay an annual premium for the D&O Insurance in excess of two
times the last annual premium paid by the Company prior to the date hereof
(which annual premium the Company represents and warrants to have been $90,274
in the aggregate), but in such case shall purchase as much coverage as possible
for such amount.
 
  Section 6.12 Employee Benefits. At the Effective Time, all employee benefits
plans and programs shall terminate, and subject to all applicable laws, and all
vested rights and benefits of such benefit plans and programs shall be
distributed to the eligible recipients in accordance with the terms of such
plans of the Company and its Subsidiaries; provided, however, that with respect
to the qualified benefit plans, the parties may elect prior to the Effective
Time to freeze benefit accruals in lieu of terminating the plans as of the
Effective Time. The officers and employees of the Company and its Subsidiaries
shall be provided with employee benefits under plans and programs which, in the
aggregate, are no less favorable than those provided pursuant to the plans and
programs of Parent and its Subsidiaries in effect on the date hereof (including
but not limited to stock option, incentive compensation, deferred compensation,
pension, life insurance, medical, profit sharing (including 401(k)), severance,
salary continuation and fringe benefits). If Parent or any of its Subsidiaries
shall at any time provide benefits to retirees of Parent or any of its
Subsidiaries, retirees of the Company and its Subsidiaries shall be provided
benefits which, in the aggregate, are no less favorable than those provided to
retirees of Parent and its Subsidiaries. For purposes of eligibility to
participate in and vesting in all benefits provided to retirees, officers and
employees, individuals who are retirees, officers and employees of the Company
and its Subsidiaries as of the Effective Time or who are thereafter employed
pursuant to Section 6.13(e) will be credited with their years of service with
the Company and its Subsidiaries and years of service with prior employers to
the extent service with prior employers is taken into account under analogous
plans of the Company. With respect to officers or employees of the Company or
its Subsidiaries at the Effective Time who become eligible to participate in
the medical plan of Parent, (i) no condition that was eligible for coverage
under any medical plan of the Company shall be excluded from coverage under the
medical plan of Parent as a pre-existing condition and (ii) amounts paid before
the Effective Time by officers and employees of the Company under any medical
plans of the Company with respect to the plan year containing the Effective
Time shall after the Effective Time be taken into account in applying
deductibles and maximum out-of-pocket limits applicable under the medical plan
of Parent provided as of the Effective Time with respect to the balance of such
plan year to the same extent as if such amounts had been paid under such
medical plan of Parent.
 
  Section 6.13 Stay Bonuses; Merit Bonuses; Severance Policy. (a) From the date
hereof up to the Effective Time, after consultation with Parent, the Company
shall be permitted to offer and pay bonuses, in addition to any bonuses or
payments pursuant to any existing bonus or incentive plans of the Company,
 
                                      I-31
<PAGE>
 
payable to (i) non-officer employees who remain in the employ of the Company or
its Subsidiaries until a date set by the Company, which date shall be no
earlier than the date three months after the Effective Time ("Company Stay
Bonuses"), or (ii) non-officer employees whose performance and dedication to
the Company or its Subsidiaries merits, in the discretion of the Chief
Executive Officer of the Company, special compensation ("Company Merit
Bonuses"); provided, however, that the aggregate amount paid by the Company
pursuant to such Company Stay Bonuses and Company Merit Bonuses shall be no
greater than $625,000.
 
  (b) From the date hereof up to the Effective Time, after consultation with
the Company, Parent shall be permitted to offer and pay bonuses, in addition to
any bonuses or payments pursuant to any existing bonus or incentive plans of
Parent, payable to (i) non-officer employees who remain in the employ of Parent
or its Subsidiaries until a date set by Parent, which date shall be no earlier
than the date three months after the Effective Time ("Parent Stay Bonuses"), or
(ii) non-officer employees whose performance and dedication to Parent or its
Subsidiaries merits, in the discretion of the Chief Executive Officer of
Parent, special compensation ("Parent Merit Bonuses"); provided, however, that
the aggregate amount paid by Parent pursuant to such Parent Stay Bonuses and
Parent Merit Bonuses shall be no greater than $625,000.
 
  (c) With respect to officers and employees who are or will be terminated,
Parent shall maintain the Company's severance policy as in effect on the date
hereof, or shall replace such policy with a policy providing equal or more
favorable compensation, for a period of at least two years from the Effective
Time.
 
  (d) Parent shall honor or cause to be honored all severance and employment
agreements that existed as of February 15, 1995 with the Company's officers and
employees. The Company has provided to Parent a true, correct and complete copy
of each such severance agreement and employment agreement with the Company's
officers and employees. The Company represents and warrants that it has not
entered into any such severance or employment agreements after February 15,
1995.
 
  (e) To the extent not inconsistent with any applicable law or regulation, for
one year after the Effective Time, before filling any job vacancy or newly
created position, Parent and its Subsidiaries will undertake reasonable efforts
to send written notification of such vacancy or position to any officers or
employees of the Company and its Subsidiaries who were terminated subsequent to
the Effective Time by the Company, the Parent, or a Subsidiary of either of
them and who had been employed in a comparable position at the Effective Time.
Determination of a comparable position shall be solely in the reasonable
discretion of the Parent and its Subsidiaries. Any such notice will be sent to
the address of the employee last appearing on the records of the Company. Upon
sending any such notice, the Company shall have satisfied its obligations
hereunder.
 
  In addition to the matters set forth above, if any former employee of the
Company or its Subsidiaries is hired by Parent or its Subsidiaries in
accordance with this Section 6.13(e) within one year after the Effective Time,
the years of service of such employee with the Company, its Subsidiaries and
any prior employer shall be credited for purposes of eligibility and vesting as
provided in Section 6.12 and, in the case of employment opportunities requiring
a relocation of the employee's place of residence, such employee will be
provided relocation expenses and reimbursement under Parent's reimbursement
policy for transferred or newly hired employees in effect on the date hereof.
 
  (f) Promptly after the Effective Time, Parent and its Subsidiaries shall
enter into an agreement with a professional outplacement agency to provide
reasonable and customary outplacement services ("Outplacement Services") to
officers and employees of the Company and its Subsidiaries who are terminated
as a result of, or within eighteen months following, the Merger, which
Outplacement Services provided to Senior Management shall include one-on-one
counseling and assistance; provided, however, that the aggregate amount paid by
the Parent and its Subsidiaries in connection with such Outplacement Services
shall be no greater than $100,000. For purposes of this Section 6.13(f),
"Senior Management" means those individuals identified in Section 6.13(f) of
the Company Disclosure Schedule.
 
                                      I-32
<PAGE>
 
                                  ARTICLE VII
 
                       Conditions Precedent to the Merger
 
  Section 7.1 Conditions to Each Party's Obligation to Effect the Merger. The
respective obligations of each party to effect the Merger shall be subject to
the fulfillment or waiver (where permissible) at or prior to the Effective Time
of each of the following conditions:
 
    (a) Stockholder Approval. The Merger shall have been approved by the
  requisite vote of the holders of Company Common Stock, and the Charter
  Amendment and Share Issuance shall have been approved by the requisite vote
  of the holders of Parent Common Stock.
 
    (b) NYSE Listing. The Parent Common Stock issuable in the Merger and
  pursuant to the Company Stock Options shall have been authorized for
  listing on the NYSE, upon official notice of issuance.
 
    (c) Improvements Act Waiting Period. The applicable waiting period under
  the Improvements Act shall have expired or been terminated.
 
    (d) Registration Statement. The Registration Statement shall have become
  effective in accordance with the provisions of the Securities Act. No stop
  order suspending the effectiveness of the Registration Statement shall have
  been issued by the SEC and remain in effect. All necessary state securities
  or "Blue Sky" authorizations shall have been received.
 
    (e) No Order. No Governmental Entity or court of competent jurisdiction
  shall have enacted, issued, promulgated, enforced or entered any law, rule,
  regulation, executive order, decree, injunction or other order (whether
  temporary, preliminary or permanent) which is then in effect and has the
  effect of prohibiting the Merger or the transactions contemplated hereby;
  provided that, in the case of any such decree, injunction or other order,
  each of the parties shall have used reasonable best efforts to prevent the
  entry of any such injunction or other order and to appeal as promptly as
  practicable any decree, injunction or other order that may be entered.
 
    (f) Other Approvals. All authorizations, consents, orders, declarations
  or approvals of, or filings with, or terminations or expirations of waiting
  periods imposed by, any Governmental Entity, the failure to obtain which
  would have a Material Adverse Effect on Parent (assuming the Merger had
  taken place) shall have been obtained, shall have occurred or shall have
  been filed.
 
  Section 7.2 Conditions to Obligation of the Company to Effect the Merger. The
obligation of the Company to effect the Merger shall be subject to the
fulfillment at or prior to the Effective Time of the following additional
conditions; provided that the Company may waive any of such conditions in its
sole discretion:
 
    (a) Performance of Obligations; Representations and Warranties. Parent
  and Sub shall have performed in all material respects each of their
  agreements contained in this Agreement required to be performed on or prior
  to the Effective Time, each of the representations and warranties of Parent
  and Sub contained in this Agreement that is qualified by materiality shall
  be true and correct on and as of the Effective Time as if made on and as of
  such date and each of the representations and warranties that is not so
  qualified shall be true and correct in all material respects on and as of
  the Effective Time as if made on and as of such date, in each case except
  as contemplated or permitted by this Agreement.
 
    (b) Officers' Certificate. Parent shall have furnished to the Company a
  certificate, dated the Effective Time, signed by the appropriate officers
  of Parent, certifying to the effect that to the best of the knowledge and
  belief of each of them, the conditions set forth in this Section 7.2(a)
  have been satisfied in full.
 
    (c) Opinion of Bearman Talesnick & Clowdus Professional Corporation. The
  Company shall have received an opinion from Bearman Talesnick & Clowdus
  Professional Corporation, dated the Effective Time, substantially to the
  effect that:
 
 
                                      I-33
<PAGE>
 
      (i) The incorporation, existence and good standing of Parent and Sub
    are as stated in this Agreement; the authorized shares of Parent and
    Sub are as stated in this Agreement; all outstanding shares of Parent
    Common Stock are duly and validly authorized and issued, fully paid and
    nonassessable and have not been issued in violation of any preemptive
    right of any stockholders.
 
      (ii) Each of Parent and Sub has full corporate power and authority to
    execute, deliver and perform this Agreement and this Agreement has been
    duly authorized, executed and delivered by Parent or Sub, as the case
    may be, and (assuming due and valid authorization, execution and
    delivery by the Company) constitutes the legal, valid and binding
    agreement of Parent or Sub.
 
      (iii) The execution and performance by Parent and Sub of this
    Agreement will not violate the Certificates of Incorporation or By-Laws
    of Parent and Sub, respectively, and, to the knowledge of such counsel,
    will not violate, result in a breach of or constitute a default under
    any material lease, mortgage, contract, agreement, instrument, law,
    rule, regulation, judgment, order or decree to which Parent and Sub is
    a party or by which they or any of their properties or assets may be
    bound.
 
      (iv) To the knowledge of such counsel, no consent, approval,
    authorization or order of any court or governmental agency or body
    which has not been obtained is required on behalf of Parent and Sub for
    the consummation of the transactions contemplated by this Agreement.
 
      (v) To the knowledge of such counsel, there are no actions, suits or
    proceedings, pending or threatened against or affecting Parent, its
    Significant Subsidiaries or Sub, by any Governmental Entity which seek
    to restrain, prohibit or invalidate the transactions contemplated by
    this Agreement.
 
      (vi) (A) At the time the Registration Statement became effective, the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by the Company as to which such
    counsel expresses no opinion) complied as to form in all material
    respects with the requirements of the Securities Act and the rules and
    regulations of the SEC thereunder.
 
      (B) In the course of the preparation of the Registration Statement
    and the Proxy Statement such counsel has considered the information set
    forth therein in light of the matters required to be set forth therein,
    and has participated in conferences with officers and representatives
    of the Company and Parent, including their respective counsel and
    independent public accountants, during the course of which the contents
    of the Registration Statement and the Proxy Statement and related
    matters were discussed. Such counsel has not independently checked the
    accuracy or completeness of, or otherwise verified, and accordingly is
    not passing upon, and does not assume responsibility for, the accuracy,
    completeness or fairness of the statements contained in the
    Registration Statement or the Proxy Statement; and such counsel has
    relied as to materiality, to a large extent, upon the judgment of
    officers and representatives of the Company and Parent. However, as a
    result of such consideration and participation, nothing has come to
    such counsel's attention which causes such counsel to believe that the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by the Company as to which such
    counsel expresses no belief), at the time it became effective,
    contained any untrue statement of a material fact or omitted to state a
    material fact required to be stated therein or necessary to make the
    statements therein not misleading or that the Proxy Statement (other
    than the financial statements, financial data, statistical data and
    supporting schedules included therein, and information relating to or
    supplied by the Company, as to which such counsel expresses no belief),
    at the time the Registration Statement became effective, at the time of
    mailing or at the time of the Stockholder Meetings, included any untrue
    statement of a material fact or omitted to state a material fact
    necessary in order to make the statements therein, in the light of the
    circumstances under which they were made, not misleading.
 
 
                                      I-34
<PAGE>
 
      (vii) The shares of Parent Common Stock to be issued pursuant to this
    Agreement will be, when so issued, duly authorized, validly issued and
    outstanding, fully paid and nonassessable.
 
      (viii) The shares of Parent Common Stock included in the Registration
    Statement have been listed on the NYSE subject to official notice of
    issuance and evidence of satisfactory distribution.
 
  In rendering such opinion, counsel for Parent may rely as to matters of
  fact upon the representations of officers of Parent or Sub contained in any
  certificate delivered to such counsel and certificates of public officials.
  Such opinion shall be limited to the General Corporation Law of the State
  of Delaware and the laws of the United States of America and the State of
  Colorado.
 
    (d) Opinion of Simpson Thacher & Bartlett. The Company shall have
  received an opinion from Simpson Thacher & Bartlett, dated the Effective
  Time, substantially to the effect that:
 
      (i) (A) At the time the Registration Statement became effective, the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by the Company as to which such
    counsel expresses no opinion) complied as to form in all material
    respects with the requirements of the Securities Act and the rules and
    regulations of the SEC thereunder.
 
      (B) In the course of the preparation of the Registration Statement
    and the Proxy Statement such counsel has considered the information set
    forth therein in light of the matters required to be set forth therein,
    and has participated in conferences with officers and representatives
    of the Company and Parent, including their respective counsel and
    independent public accountants, during the course of which the contents
    of the Registration Statement and the Proxy Statement and related
    matters were discussed. Such counsel has not independently checked the
    accuracy or completeness of, or otherwise verified, and accordingly is
    not passing upon, and does not assume responsibility for, the accuracy,
    completeness or fairness of the statements contained in the
    Registration Statement or the Proxy Statement; and such counsel has
    relied as to materiality, to a large extent, upon the judgment of
    officers and representatives of the Company and Parent. However, as a
    result of such consideration and participation, nothing has come to
    such counsel's attention which causes such counsel to believe that the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by the Company as to which such
    counsel expresses no belief), at the time it became effective,
    contained any untrue statement of a material fact or omitted to state a
    material fact required to be stated therein or necessary to make the
    statements therein not misleading or that the Proxy Statement (other
    than the financial statements, financial data, statistical data and
    supporting schedules included therein, and information relating to or
    supplied by the Company, as to which such counsel expresses no belief),
    at the time the Registration Statement became effective, at the time of
    mailing or at the time of the Stockholder Meetings, included any untrue
    statement of a material fact or omitted to state a material fact
    necessary in order to make the statements therein, in the light of the
    circumstances under which they were made, not misleading.
 
      (ii) The shares of Parent Common Stock to be issued pursuant to this
    Agreement will be, when so issued, duly authorized, validly issued and
    outstanding, fully paid and nonassessable.
 
      (iii) The shares of Parent Common Stock included in the Registration
    Statement have been listed on the NYSE subject to official notice of
    issuance and evidence of satisfactory distribution.
 
  In rendering such opinion, counsel for Parent may rely as to matters of
  fact upon the representations of officers of Parent or Sub contained in any
  certificate delivered to such counsel and certificates of public officials.
  Such opinion shall be limited to the General Corporation Law of the State
  of Delaware and the laws of the United States of America.
 
    (e) Parent Board of Directors. Parent's Board of Directors shall have
  taken all necessary and appropriate actions to cause the number of
  directors comprising the full Board of Directors of Parent at the Effective
  Time to be increased by four and the vacancies thus created to be filled at
  the Effective
 
                                      I-35
<PAGE>
 
  Time by the election of four new directors, each of whom shall have been
  designated by the Company prior to the Effective Time.
 
    Section 7.3 Conditions to Obligations of Parent and Sub to Effect the
  Merger. The obligations of Parent and Sub to effect the Merger shall be
  subject to the fulfillment at or prior to the Effective Time of the
  following additional conditions, provided that Parent may waive any such
  conditions in its sole discretion:
 
    (a) Performance of Obligations; Representations and Warranties. The
  Company shall have performed in all material respects each of its
  agreements contained in this Agreement required to be performed on or prior
  to the Effective Time, each of the representations and warranties of the
  Company contained in this Agreement that is qualified by materiality shall
  be true and correct on and as of the Effective Time as if made on and as of
  such date and each of the representations and warranties that is not so
  qualified shall be true in all material respects on and as of the Effective
  Time as if made on and as of such date, in each case except as contemplated
  or permitted by this Agreement.
 
    (b) Third Party Consents. All required authorizations, consents or
  approvals of any third party (other than a Governmental Entity), the
  failure to obtain which would have a Material Adverse Effect on Parent
  (assuming the Merger had taken place), shall have been obtained.
 
    (c) Accounting. Based on the advice of Arthur Andersen LLP and such other
  advice as Parent may deem relevant, Parent shall have no reasonable basis
  for believing that following the Merger, the combination of the Company and
  Sub may not be accounted for as a "pooling of interests" in accordance with
  generally accepted accounting principles.
 
    (d) Officers' Certificate. The Company shall have furnished to Parent a
  certificate, dated the Effective Time, signed by the appropriate officers
  of the Company, certifying to the effect that to the best of the knowledge
  and belief of each of them, the conditions set forth in this Section 7.3(a)
  have been satisfied.
 
    (e) Opinion of Sidley & Austin. Parent shall have received an opinion of
  counsel from Sidley & Austin, special counsel to the Company, dated the
  Effective Time, substantially to the effect that:
 
      (i) The incorporation, existence, good standing and capitalization of
    the Company are as stated in this Agreement; the authorized shares of
    Company Common Stock are as stated in this Agreement; all outstanding
    shares of Company Common Stock are duly and validly authorized and
    issued, fully paid and non-assessable and have not been issued in
    violation of any preemptive right of stockholders; and, to the
    knowledge of such counsel, there is no existing option, warrant, right,
    call, subscription or other agreement or commitment obligating the
    Company to issue or sell, or to purchase or redeem, any shares of its
    capital stock other than as stated in this Agreement.
 
      (ii) The Company has full corporate power and authority to execute,
    deliver and perform this Agreement and this Agreement has been duly
    authorized, executed and delivered by the Company, and (assuming the
    due and valid authorization, execution and delivery by Parent and Sub)
    constitutes the legal, valid and binding agreement of the Company.
 
      (iii) To the knowledge of such counsel, there are no actions, suits
    or proceedings, pending or threatened against or affecting the Company
    or its Significant Subsidiaries, by any Governmental Entity which seek
    to restrain, prohibit or invalidate the transactions contemplated by
    this Agreement.
 
      (iv) The execution and performance by the Company of this Agreement
    will not violate the Certificate of Incorporation or By-laws of the
    Company.
 
      (v) To the knowledge of such counsel, no consent, approval,
    authorization or order of any court or governmental agency or body
    which has not been obtained is required on behalf of the Company or any
    of its Subsidiaries for consummation of the transactions contemplated
    by this Agreement.
 
 
                                      I-36
<PAGE>
 
      (vi)  (A) At the time the Registration Statement became effective,
    the Registration Statement (other than the financial statements,
    financial data, statistical data and supporting schedules included
    therein, and information relating to or supplied by Parent or Sub as to
    which such counsel expresses no opinion) complied as to form in all
    material respects with the requirements of the Securities Act and the
    rules and regulations of the SEC thereunder.
 
      (B) In the course of the preparation of the Registration Statement
    and the Proxy Statement such counsel has considered the information set
    forth therein in light of the matters required to be set forth therein,
    and has participated in conferences with officers and representatives
    of the Company and Parent, including their respective counsel and
    independent public accountants, during the course of which the contents
    of the Registration Statement and the Proxy Statement and related
    matters were discussed. Such counsel has not independently checked the
    accuracy or completeness of, or otherwise verified, and accordingly is
    not passing upon, and does not assume responsibility for, the accuracy,
    completeness or fairness of the statements contained in the
    Registration Statement or the Proxy Statement; and such counsel has
    relied as to materiality, to a large extent, upon the judgment of
    officers and representatives of the Company and Parent. However, as a
    result of such consideration and participation, nothing has come to
    such counsel's attention which causes such counsel to believe that the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by or Parent or Sub, as to which
    such counsel expresses no belief), at the time it became effective,
    contained any untrue statement of a material fact or omitted to state a
    material fact required to be stated therein or necessary to make the
    statements therein not misleading or that the Proxy Statement (other
    than the financial statements, financial data, statistical data and
    supporting schedules included therein, and information relating to or
    supplied by Parent or Sub, as to which such counsel expresses no
    belief), at the time the Registration Statement became effective, at
    the time of mailing or at the time of the Stockholder Meetings,
    included any untrue statement of a material fact or omitted to state a
    material fact necessary in order to make the statements therein, in the
    light of the circumstances under which they were made, not misleading.
 
  In rendering such opinion, counsel for the Company may rely as to matters
  of fact upon the representations of officers of the Company and its
  Subsidiaries contained in any certificate delivered to such counsel and
  certificates of public officials.
 
    Such opinion should be limited to the General Corporation Law of the
  State of Delaware and the laws of the United States of America.
 
    (f) Opinion of General Counsel. Parent shall have received an opinion of
  counsel from Eugene A. Lang, Jr., General Counsel to the Company, dated the
  Effective Time, substantially to the effect that:
 
      (i) The incorporation, existence and good standing of Significant
    Subsidiaries are as stated in this Agreement.
 
      (ii) All of the issued and outstanding shares of capital stock of
    Significant Subsidiaries are owned of record and, to the knowledge of
    such counsel, beneficially by the Company, and such counsel is aware of
    no liens, charges and encumbrances on any such shares.
 
      (iii) To the knowledge of such counsel, there is no existing option,
    warrant, right, call, subscription or other agreement or commitment
    obligating the Company or Significant Subsidiaries to issue or sell, or
    to purchase or redeem, any shares of capital stock of Significant
    Subsidiaries.
 
      (iv) The execution and performance by the Company of this Agreement
    will not violate the Certificate of Incorporation or By-laws of any of
    the Company's Subsidiaries, and, to the knowledge of such counsel, will
    not violate, result in a breach of, or constitute a default under, any
    material lease, mortgage, contract, agreement, instrument, law, rule,
    regulation, judgment, order or decree to which the Company or any of
    its Subsidiaries is a party or to which they or any of their properties
    or assets may be bound.
 
 
                                      I-37
<PAGE>
 
      (v) In the course of the preparation of the Registration Statement
    and the Proxy Statement such counsel has considered the information set
    forth therein in light of the matters required to be set forth therein,
    and has participated in conferences with officers and representatives
    of the Company and Parent, including their respective counsel and
    independent public accountants, during the course of which the contents
    of the Registration Statement and the Proxy Statement and related
    matters were discussed. Such counsel has not independently checked the
    accuracy or completeness of, or otherwise verified, and accordingly is
    not passing upon, and does not assume responsibility for, the accuracy,
    completeness or fairness of the statements contained in the
    Registration Statement or the Proxy Statement; and such counsel has
    relied as to materiality, to a large extent, upon the judgment of
    officers and representatives of the Company and Parent. However, as a
    result of such consideration and participation, nothing has come to
    such counsel's attention which causes such counsel to believe that the
    Registration Statement (other than the financial statements, financial
    data, statistical data and supporting schedules included therein, and
    information relating to or supplied by or Parent or Sub, as to which
    such counsel expresses no belief), at the time it became effective,
    contained any untrue statement of a material fact or omitted to state a
    material fact required to be stated therein or necessary to make the
    statements therein not misleading or that the Proxy Statement (other
    than the financial statements, financial data, statistical data and
    supporting schedules included therein, and information relating to or
    supplied by Parent or Sub, as to which such counsel expresses no
    belief), at the time the Registration Statement became effective, at
    the time of mailing or at the time of the Stockholder Meetings,
    included any untrue statement of a material fact or omitted to state a
    material fact necessary in order to make the statements therein, in the
    light of the circumstances under which they were made, not misleading.
 
  In rendering such opinion, such counsel for the Company may rely as to
  matters of fact upon the representations of officers of the Company and its
  Subsidiaries contained in any certificate delivered to such counsel and
  certificates of public officials.
 
  Such opinion should be limited to the General Corporation Law of the State of
Delaware and the laws of the United States of America and the State of
Colorado.
 
                                  ARTICLE VIII
 
                       Termination, Amendment and Waiver
 
  Section 8.1 Termination. This Agreement may be terminated at any time prior
to the Effective Time, whether before or after any approval by the stockholders
of the Company:
 
    (a) by mutual written consent of Parent and the Company;
 
    (b) by Parent if (i) the Company shall have failed to comply in any
  material respect with any of its covenants or agreements contained in this
  Agreement required to be complied with by the Company prior to the date of
  such termination, which failure to comply has not been cured within five
  business days following receipt by the Company of notice of such failure to
  comply, (ii) the stockholders of the Company shall have failed to approve
  the Merger at the Company Stockholder Meeting, or (iii) the stockholders of
  Parent shall have failed to approve the Charter Amendment or the Share
  Issuance at the Parent Stockholder Meeting;
 
    (c) by the Company if (i) Parent or Sub shall have failed to comply in
  any material respect with any of its covenants or agreements contained in
  this Agreement required to be complied with by Parent or Sub prior to the
  date of such termination, which failure to comply has not been cured within
  five business days following receipt by Parent of notice of such failure to
  comply, (ii) the stockholders of the Company shall have failed to approve
  the Merger at the Company Stockholder Meeting, or (iii) the stockholders of
  Parent shall have failed to approve the Charter Amendment or the Share
  Issuance at the Parent Stockholder Meeting;
 
                                      I-38
<PAGE>
 
    (d) by either Parent or the Company if (i) the Merger has not been
  effected on or prior to the close of business on December 31, 1995;
  provided, however, that the right to terminate this Agreement pursuant to
  this clause shall not be available to any party whose failure to fulfill
  any obligation of this Agreement has been the cause of, or resulted in, the
  failure of the Merger to have occurred on or prior to the aforesaid date,
  or (ii) any court of competent jurisdiction or any governmental,
  administrative or regulatory authority, agency or body shall have issued an
  order, decree or ruling or taken any other action permanently enjoining,
  restraining or otherwise prohibiting the transactions contemplated by this
  Agreement and such order, decree, ruling or other action shall have become
  final and nonappealable;
 
    (e) by either Parent or the Company if there has been (i) a material
  breach by the other of any representation or warranty that is not qualified
  as to materiality or (ii) a breach by the other of any representation or
  warranty that is qualified as to materiality, in each case which breach has
  not been cured within five business days following receipt by the breaching
  party of notice of the breach;
 
    (f) by Parent, (i) if the Board of Directors of the Company shall not
  have recommended, or shall have resolved not to recommend, or shall have
  modified or withdrawn its recommendation of the Merger or declaration that
  the Merger is fair to and advisable and in the best interest of the Company
  and its stockholders, or shall have resolved to do so, or (ii) if the Board
  of Directors of the Company shall have recommended, or shall have resolved
  to recommend, to the stockholders of the Company any takeover proposal or
  offer for the Company;
 
    (g) by the Company if the Board of Directors of Parent shall not have
  recommended, or shall have resolved not to recommend, or shall have
  modified or withdrawn its recommendation of this Agreement, the Charter
  Amendment and the Share Issuance or declaration that such transactions are
  fair to and advisable and in the best interest of Parent and its
  stockholders, or shall have resolved to do so;
 
    (h) by the Company if there is an offer to acquire all of the outstanding
  shares of Company Common Stock or substantially all of the assets of the
  Company for consideration that provides stockholders of the Company a value
  per share of Company Common Stock which, in the good faith judgment of the
  Board of Directors of the Company, provides a higher value per share than
  the consideration per share pursuant to the Merger; or
 
    (i) by Parent, if a Third Party Acquisition occurs.
 
  Section 8.2 Effect of Termination. In the event of termination of this
Agreement by either Parent or the Company, as provided in Section 8.1, this
Agreement shall forthwith become void and there shall be no liability hereunder
on the part of the Company, Parent or Sub or their respective officers or
directors (except as set forth in the last three sentences of Section 6.3(a)
and (b), which shall survive the termination); provided, however, that nothing
contained in this Section 8.2 shall relieve any party hereto from any liability
for any breach of this Agreement; and provided, further, that, (i) any
termination under Section 8.1(h) shall not become effective until the fee
required to be paid pursuant to Section 6.6(b)(iv) shall have been paid to
Parent, (ii) if this Agreement is terminated pursuant to Sections 8.1(b)(i) or
8.1(e), the provisions of Section 6.6(b)(i) shall survive until any payments
required to be made thereunder are made, (iii) if this Agreement is terminated
pursuant to Section 8.1(b)(ii) or Section 8.1(c)(ii), the provisions of Section
6.6(b)(ii) shall survive until any payments required to be made thereunder are
made, (iv) if this Agreement is terminated pursuant to Section 8.1(f)(i), the
provisions of Section 6.6(b)(iii) shall survive until any payments required to
be made thereunder are made, and (v) if this Agreement is terminated pursuant
to Sections 8.1(f)(ii) or 8.1(i), the provisions of Section 6.6(b)(iv) shall
survive until any payments required to be made thereunder are made.
 
  Section 8.3 Amendment. This Agreement may be amended by the parties hereto,
by or pursuant to action taken by their respective Boards of Directors, at any
time before or after approval of the Merger by the stockholders of the Company
but, after any such approval by stockholders of the Company, no amend ment
shall be made which changes the Exchange Ratio as provided in Section 1.5 or
which in any way materially adversely affects the rights of such stockholders,
without the further approval of such stockholders. This Agreement may not be
amended except by an instrument in writing signed on behalf of each of the
parties hereto.
 
                                      I-39
<PAGE>
 
  Section 8.4 Waiver. At any time prior to the Effective Time, the parties
hereto may (i) extend the time for the performance of any of the obligations or
other acts of the other parties hereto, (ii) waive any inaccuracies in the
representations and warranties contained herein or in any document delivered
pursuant hereto and (iii) waive compliance with any of the agreements or
conditions contained herein which may legally be waived. Any agreement on the
part of a party hereto to any such extension or waiver shall be valid only if
set forth in an instrument in writing signed on behalf of such party.
 
                                   ARTICLE IX
 
                               General Provisions
 
  Section 9.1 Non-Survival of Representations and Warranties. None of the
representations and warranties in this Agreement or in any instrument delivered
pursuant to this Agreement shall survive the Effective Time.
 
  Section 9.2 Notices. All notices and other communications hereunder shall be
in writing and shall be deemed given if delivered personally, sent by overnight
courier or telecopied (with a confirmatory copy sent by overnight courier) to
the parties at the following addresses (or at such other address for a party as
shall be specified by like notice):
 
  (a) if to Parent or Sub, to
 
    Barrett Resources Corporation
    1125 Seventeenth Street
    Barrett Resources Corporation
    Suite 2400
    Denver, Colorado 80202
    Attention: J. Frank Keller
                Executive Vice President
 
  with copies to:
 
    Alan L. Talesnick
    Bearman Talesnick & Clowdus P.C.
    1200 Seventeenth Street, Suite 2600
    Denver, Colorado 80202
 
      and
 
    John W. Carr
    Simpson Thacher & Bartlett
    425 Lexington Avenue
    New York, New York 10017
 
                                      I-40
<PAGE>
 
  (b) if to the Company, to
 
    Plains Petroleum Company
    12596 West Bayaud Avenue, Suite 400
    Lakewood, Colorado 80228
    Attention: James A. Miller, Chairman and
                Chief Executive Officer
 
  with copies to:
 
    Eugene A. Lang, Jr.
    Plains Petroleum Company
    12596 West Bayaud Avenue, Suite 400
    Lakewood, Colorado 80228
 
      and
 
    Thomas A. Cole
    Sidley & Austin
    One First National Plaza
    Chicago, Illinois 60603
 
  Section 9.3 Interpretation. When a reference is made in this Agreement to a
Section, such reference shall be to a Section of this Agreement unless
otherwise indicated, and the words "hereof", "herein" and "hereunder" and
similar terms refer to this Agreement as a whole and not to any particular
provision of this Agreement, unless the context otherwise requires. The table
of contents and headings contained in this Agreement are for reference purposes
only and shall not affect in any way the meaning or interpretation of this
Agreement. Whenever the words "include," "includes" or "including" are used in
this Agreement, they shall be deemed to be followed by the words "without
limitation."
 
  Section 9.4 Counterparts. This Agreement may be executed in counterparts, all
of which shall be considered one and the same agreement and shall become
effective when one or more counterparts have been signed by each of the parties
and delivered to the other parties.
 
  Section 9.5 Entire Agreement; No Third-Party Beneficiaries. This Agreement,
including the documents and instruments referred to herein, (a) constitutes the
entire agreement and supersedes all prior agreements and understandings, both
written and oral, among the parties with respect to the subject matter hereof
and (b) except for the provisions of Sections 6.11, 6.12 and 6.13 (other than
Section 6.13(e)), is not intended to confer upon any person other than the
parties any rights or remedies hereunder; provided, however, that attorneys for
the parties hereto may rely upon the representations and warranties contained
herein and in the certificates delivered pursuant to Sections 7.2(b) and
7.3(d).
 
  Section 9.6 Governing Law. This Agreement shall be governed by, and construed
in accordance with, the laws of the State of Delaware, regardless of the laws
that might otherwise govern under applicable principles of conflicts of laws
thereof.
 
  Section 9.7 Assignment. Neither this Agreement nor any of the rights,
interests or obligations hereunder shall be assigned by any of the parties
without the prior written consent of the other parties, except that Sub may
assign, in its sole discretion, any of or all its rights, interests and
obligations under this Agreement to Parent or to any direct or indirect wholly-
owned subsidiary of Parent, but no such assignment shall relieve Sub of any of
its obligations hereunder. Subject to the preceding sentence, this Agreement
shall be binding upon, inure to the benefit of, and be enforceable by, the
parties and their respective successors and assigns.
 
  Section 9.8 Severability. If any term or other provision of this Agreement is
invalid, illegal or incapable of being enforced by any rule of law, or public
policy, all other conditions and provisions of this
 
                                      I-41
<PAGE>
 
Agreement shall nevertheless remain in full force and effect so long as the
economic or legal substance of the transactions contemplated hereby are not
affected in any manner materially adverse to any party. Upon such determination
that any term or other provision is invalid, illegal or incapable of being
enforced, the parties shall negotiate in good faith to modify this Agreement so
as to effect the original intent of the parties as closely as possible in a
mutually acceptable manner in order that the transactions be consummated as
originally contemplated to the fullest extent possible.
 
  Section 9.9 Enforcement of This Agreement. The parties agree that irreparable
damage would occur in the event that any of the provisions of this Agreement
were not performed in accordance with their specific terms or were otherwise
breached. It is accordingly agreed that the parties shall be entitled to an
injunction or injunctions to prevent breaches of this Agreement and to enforce
specifically the terms and provisions hereof in any court of the United States
or any state having jurisdiction, this being in addition to any other remedy to
which they are entitled at law or in equity.
 
  Section 9.10 Jurisdiction and Venue. Each party hereby irrevocably submits to
the exclusive jurisdiction of the United States District Court for the District
of Colorado or any court of the State of Delaware in any action, suit or
proceeding arising from or in connection with this Agreement, and agrees that
any such action, suit or proceeding shall be brought only in such court (and
waives any objection based on forum non conveniens or any other objection to
venue therein).
 
                                      I-42
<PAGE>
 
  IN WITNESS WHEREOF, Parent, Sub and the Company have caused this Agreement to
be signed by their respective officers thereunto duly authorized all as of the
date first written above.
 
                                          Barrett Resources Corporation
 
                                                  /s/ William J. Barrett
                                          By___________________________________
                                                    WILLIAM J. BARRETT
                                               CHAIRMAN AND CHIEF EXECUTIVE
                                                          OFFICER
 
Attest:
 
           /s/ J.F. Keller
_____________________________________
             J.F. KELLER
      EXECUTIVE VICE PRESIDENT
 
                                          Vanilla Corporation
 
                                                  /s/ William J. Barrett
                                          By___________________________________
                                                    WILLIAM J. BARRETT
                                                  CHIEF EXECUTIVE OFFICER
 
Attest:
 
           /s/ J.F. Keller
_____________________________________
             J.F. KELLER
    VICE PRESIDENT AND SECRETARY
 
                                          Plains Petroleum Company
 
                                                    /s/ James A. Miller
                                          By___________________________________
                                                      JAMES A. MILLER
                                               CHAIRMAN AND CHIEF EXECUTIVE
                                                          OFFICER
 
Attest:
 
       /s/ Eugene A. Lang, Jr.
_____________________________________
         EUGENE A. LANG, JR.
              SECRETARY
 
                                      I-43
<PAGE>
 
                                                                        ANNEX II

                              FORM OF OPINION OF 
                           PETRIE PARKMAN & CO. INC.

                                                                     June _ 1995




The Board of Directors
Barrett Resources Corporation
1125 17th Street
Suite 2400
Denver, CO  80202

Dear Sirs:

        You have asked us to advise you with respect to the fairness from a
financial point of view to the stockholders of Barrett Resources Corporation
("Barrett") of the exchange ratio (the "Exchange Ratio") of 1.30 shares of
Barrett common stock, par value $0.01 per share ("Barrett Common Stock"), per
share of Plains Petroleum Company ("Plains") common stock, par value $0.01 per
share ("Plains Common Stock"), pursuant to the terms of the merger agreement,
dated as of May 2, 1995 (the "Merger Agreement"), among Barrett, a wholly-owned
subsidiary of Barrett ("Sub"), and Plains.  The Merger Agreement provides for
the merger (the "Merger") of Sub with and into Plains pursuant to which Plains
will become a wholly-owned subsidiary of Barrett and each issued and outstanding
share of Plains Common Stock will be converted into 1.30 shares of Barrett
Common Stock.

        In arriving at our opinion, we have, among other things:

             (i)    reviewed certain publicly available business and financial
                    information relating to Plains and Barrett, including, among
                    others, audited financial statements for Plains as of
                    December 31, 1994, and Barrett as of September 30, 1994 and
                    unaudited financial and operating information for Barrett as
                    of February 28, 1995;

             (ii)   reviewed the estimates of proved oil and gas reserves as
                    prepared by Netherland Sewell & Associates, Inc. for Plains
                    as of December 31, 1994 and as reviewed by Ryder Scott
                    Company for Barrett as of September 30, 1994 and March 31,
                    1995;

             (iii)  reviewed certain estimates of oil and gas reserves of Plains
                    and Barrett as of January 1, 1995 as prepared by their
                    respective management and staff;
<PAGE>
 

             (iv)   analyzed certain internal financial and operating forecasts
                    and financial and operating data and budgets concerning
                    Plains and Barrett, all of which were prepared or provided
                    by the management of Plains or Barrett;

              (v)   discussed the current operations and prospects of Plains
                    with the management and operating staff of Plains and
                    Barrett;

             (vi)   discussed with the management and operating staff of Barrett
                    the current operations and prospects of Barrett and the
                    expected operations and prospects of the combined company,
                    giving proforma effect to the Merger, including the
                    operational efficiencies expected by Barrett to be realized
                    from the Merger;

            (vii)   reviewed the historical market prices of the shares of
                    Barrett Common Stock and Plains Common Stock;

           (viii)   compared the financial terms of the Merger with the
                    financial terms of certain other transactions which we
                    deemed to be relevant; and

             (ix)   made such other analyses and examinations as we have deemed
                    necessary or appropriate.

        We have not independently verified the information considered in our
review, and for purposes of the opinion set forth below, we have assumed and
relied upon the accuracy and completeness of such information, including without
limitation, the statements made in the discussions referred to above.  With
respect to the financial  and operating forecasts and the operational
efficiencies expected by Barrett to be realized from the Merger, we have assumed
that they have been reasonably prepared on bases reflecting the best currently
available estimates and judgments relating to the future financial and
operational performance of Plains and Barrett, and the management of Barrett has
advised us that we may assume, and we have so assumed, for purposes of this
opinion the reasonableness and achievability of such forecasts and efficiencies.
With respect to the estimates of oil and gas reserves, we have assumed that they
have been reasonably prepared on bases reflecting the best available estimates
and judgments relating to Plains' and Barrett's oil and gas properties.
Consistent with the Merger Agreement, we have assumed that the Merger will be
treated for federal income tax purposes as a reorganization within the meaning
of Section 368 of the Internal Revenue Code of 1986, as amended, and will be
treated as a "pooling of interests" for accounting purposes.  In addition, we
have not made an independent evaluation or appraisal of the assets or
liabilities of Plains or Barrett nor, except for the estimates of oil and gas
reserves referred to above, have we been furnished with such an evaluation or
appraisal.


                                     II-2
<PAGE>
 



        Our opinion relates solely to the fairness from a financial point of
view to the stockholders of Barrett of the Exchange Ratio pursuant to the
Merger.  We have not been requested to, and do not, express any opinion
regarding the fairness of the Exchange Ratio to Plains, or any stockholder of
Plains.  Our engagement and the opinion expressed herein are solely for the
benefit of Barrett's Board of Directors and are not on behalf of, and are not
intended to confer rights or remedies upon, Plains, any stockholder of Barrett
or Plains, or any person other than Barrett's Board of Directors.  This letter
may not be used for any other purpose without our prior written consent.  As you
are aware, we will receive a fee in connection with rendering this opinion and a
fee that is contingent upon the consummation of the Merger.

        Our opinion is rendered on the basis of conditions in the securities
markets and the oil and gas markets prevailing as of the date hereof and the
condition and prospects, financial and otherwise, of Plains and Barrett as they
have been represented to us as of the date hereof or as they were reflected in
the materials and discussions described above.

        Based upon and subject to the foregoing, and based upon such other
matters as we consider relevant, it is our opinion that, as of the date hereof,
the Exchange Ratio is fair from a financial point of view to the holders of
Barrett Common Stock.

                                       Very truly yours,



                                     II-3
<PAGE>
 
                                                                      ANNEX III
 
                    FORM OF OPINION OF GOLDMAN, SACHS & CO.
 
 
 
 
June 13, 1995
 
Board of Directors
Plains Petroleum Company
12596 West Bayaud, Ste. 400
Lakewood, CO 80228
 
Gentlemen:
 
  You have requested our opinion as to the fairness to the holders of the
outstanding shares of Common Stock, par value $.01 per share (the "Common
Stock"), of Plains Petroleum Company (the "Company") of the exchange ratio of
1.3 shares of Common Stock, par value $.01 per share (the "Barrett Common
Stock"), of Barrett Resources Corporation ("Barrett") to be received for each
share of Common Stock (the "Exchange Ratio") pursuant to the Agreement and
Plan of Merger dated as of May 2, 1995 among Barrett and the Company (the
"Agreement").
 
  Goldman, Sachs & Co., as part of its investment banking business, is
continually engaged in the valuation of businesses and their securities in
connection with mergers and acquisitions, negotiated underwritings,
competitive biddings, secondary distributions of listed and unlisted
securities, private placements and valuations for estate, corporate and other
purposes. We are familiar with the Company having acted as its financial
advisor in connection with, and having participated in certain of the
negotiations leading to, the Agreement.
 
  In connection with this opinion, we have reviewed, among other things, the
Agreement; Annual Reports to Stockholders and Annual Reports on Form 10-K of
the Company for the five years ended December 31, 1994 and of Barrett for the
five fiscal years ended September 30, 1994; certain interim reports to
stockholders and Quarterly Reports on Form 10-Q of the Company and Barrett to
their respective stockholders; certain other communications from the Company
and Barrett to their respective stockholders; and certain internal financial
analyses and forecasts for the Company and Barrett prepared by their
respective managements. We also have held discussions with members of the
senior management of the Company and Barrett regarding the past and current
business operations, financial condition and future prospects of their
respective companies. We have reviewed certain information provided by the
Company and Barrett relating to their respective oil and gas reserves,
including year-end reserve reports prepared by independent petroleum engineers
for the Company and Barrett, a review of interim reserves prepared by an
independent petroleum engineer for Barrett, as well as interim estimates
prepared by the Company and Barrett, and have discussed, as applicable, the
reserve information with the respective managements of the Company and Barrett
and such independent petroleum engineers. We have also held discussions with
members of the senior management of the Company and its independent petroleum
engineers regarding their due diligence
<PAGE>
 
examination of such reserve information for Barrett. We have reviewed the
reported price and trading activity for the Common Stock and the Barrett
Common Stock, compared certain financial and stock market information for the
Company and Barrett with similar information for certain other companies the
securities of which are publicly traded, reviewed the financial terms of
certain recent business combinations in the oil and gas industry specifically
and in other industries generally and performed such other studies and
analyses as we considered appropriate.
 
  We have relied without independent verification upon the accuracy and
completeness of all of the financial and other information reviewed by us for
purposes of this opinion. In addition, we have not made an independent
evaluation or appraisal of the assets and liabilities of the Company or
Barrett or any of their subsidiaries and, except for the reserve information
referred to in the third paragraph of this opinion, we have not been furnished
with any such evaluation or appraisal. With respect to such reserve
information, we are not experts in the evaluation of oil and gas properties
and, with your consent, have relied solely upon the reserve reports and
internal estimates prepared by the independent petroleum engineers and
managements of the Company and Barrett and have assumed that such information
and the forecasts provided to us have been reasonably prepared on bases
reflecting managements' best available judgments and estimates at the time of
their preparation and that the amounts reflected therein will be realized in
the amounts and at the times set forth therein. Our opinion is based upon
economic and market conditions existing on the date hereof.
 
  Based upon and subject to the foregoing and based upon such other matters as
we consider relevant, it is our opinion that as of the date hereof the
Exchange Ratio pursuant to the Agreement is fair to the holders of the Common
Stock.
 
Very truly yours,
 
 
                                     III-2
<PAGE>
 
                                                                        ANNEX IV
 
                                    GLOSSARY
 
  Unless otherwise indicated in this Joint Proxy Statement/Prospectus, natural
gas volumes are stated at the legal pressure base of the state or area in which
the reserves are located at 60(degrees) Fahrenheit. Natural gas equivalents are
determined using the ratio of six Mcf of natural gas to one barrel of crude
oil, condensate or natural gas liquids so that one barrel of oil is referred to
as six Mcf of natural gas equivalent or "Mcfe".
 
  As used in this Joint Proxy Statement/Prospectus, the following terms have
the following specific meanings: "Mcf" means thousand cubic feet, "MMcf" means
million cubic feet, "Bcf" means billion cubic feet, "Bbl" means barrel, "MBbls"
means thousand barrels, "Mcfe" means thousand cubic feet equivalent, "MMcfe"
means million cubic feet equivalent, and "MMBtu" means million British thermal
units.
 
  With respect to information concerning working interests in wells or drilling
locations, "gross" gas and oil wells or "gross" acres is the number of wells or
acres in which the respective entity has an interest, and "net" gas and oil
wells or "net" acres are determined by multiplying "gross" wells or acres by
the respective entity's working interest in those wells or acres. A working
interest in an oil and gas lease is an interest that gives the owner the right
to drill, produce, and conduct operating activities on the property and to
receive a share of production of any hydrocarbons covered by the lease. A
working interest in an oil and gas lease also entitles its owner to a
proportionate interest in any well located on the lands covered by the lease,
subject to all royalties, overriding royalties and other burdens, to all costs
and expenses of exploration, development and operation of any well located on
the lease, and to all risks in connection therewith.
 
  "Behind-pipe recompletion" is the completion of an existing well for
production from a formation that exists behind the cashing of the well.
 
  "Capital expenditures" means costs associated with exploratory and
development drilling (including exploratory dry holes); leasehold acquisitions;
seismic data acquisitions; geological, geophysical and land related overhead
expenditures; delay rentals; producing property acquisitions; and other
miscellaneous capital expenditures. "Reserve replacement cost" means the cost
of additions to the entity's reserve base divided by the aggregate costs of
developing or acquiring those additional reserves.
 
  A "development well" is a well drilled as an additional well to the same
horizon or horizons as other producing wells on a prospect, or a well drilled
on a spacing unit adjacent to a spacing unit with an existing well capable of
commercial production and which is intended to extend the proven limits of a
prospect. An "exploratory well" is a well drilled to find commercially
productive hydrocarbons in an unproved area, or to extend significantly a known
prospect.
 
  A "farm-out" is an assignment to another party of an interest in a drilling
location and related acreage conditional upon the drilling of a well on that
location. A "farm-in" is an assignment by the owner of a working interest in an
oil and gas lease of the working interest or a portion thereof to another party
who desires to drill on the leased acreage. Generally, the assignee is required
to drill one or more wells in order to earn its interest in the acreage. The
assignor usually retains a royalty or reversionary working interest in the
lease. The assignee is said to have "farmed-in" the acreage.
 
  "Reserves" means natural gas and crude oil, condensate and natural gas
liquids on a net revenue interest basis, found to be commercially recoverable.
"Proved developed reserves" includes proved developed producing reserves and
proved developed behind-pipe reserves. "Proved developed producing reserves"
includes only those reserves expected to be recovered from existing completion
intervals in existing wells. "Proved developed behind-pipe reserves" includes
those reserves that exist behind the casing of existing wells when the cost of
making such reserves available for production is relatively small compared to
the cost of a new well. "Proved undeveloped reserves" includes those reserves
expected to be recovered from new wells on proved undrilled acreage or from
existing wells where a relatively major expenditure is required for
recompletion.
<PAGE>
 
                                    PART II

                   INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 20. Indemnification of Directors and Officers

     The Delaware General Corporation Law provides for indemnification by a
corporation of costs incurred by directors, employees, and agents in connection
with an action, suit, or proceeding brought by reason of their  position as a
director, employee, or agent. The person being indemnified must have acted in
good faith and in a manner he reasonably believed to be in or not opposed to the
best interests of the corporation.

     In addition to the general indemnification section, Delaware law provides
further protection for directors under Section 102(b)(7) of the General
Corporation Law of Delaware. This section was enacted in June 1986 and allows a
Delaware corporation to include in its certificate of incorporation a provision
that eliminates and limits certain personal liability of a director for monetary
damages for certain breaches of the director's fiduciary duty of care, provided
that any such provision does not (in the words of the statute) do any of the
follows:

     "eliminate or limit the liability of a director (i) for any breach of the
     director's duty of loyalty to the corporation or its stockholders, (ii) for
     acts or omissions not in good faith or which involve intentional misconduct
     or a knowing violation of law, (iii) under section 174 of this Title
     [dealing with willful or negligent violation of the statutory provision
     concerning dividends and stock purchases and redemptions], or (iv) for any
     transaction from which the director derived an improper personal benefit.
     No such provision shall eliminate or limit the liability of a director for
     any act or omission occurring prior to the date when such provision becomes
     effective.... "

     The Board of Directors is empowered to make other indemnification as
authorized by the Certificate of Incorporation, Bylaws or corporate resolution
so long as the indemnification is consistent with the Delaware General
Corporation Law. Under the Company's by-laws, the Company is required to
indemnify its directors to the full extent permitted by the Delaware General
Corporation Law, common law and any other statutory provision.

                                     II-1
<PAGE>
 
<TABLE>
<CAPTION>
Item 21.  Exhibits

 
Exhibit No.                         Description
- -----------                         ----------- 
<S>          <C> 
2.1          Agreement and Plan of Merger, dated as of May 2, 1995, among
             Barrett Resources Corporation ("Barrett"), Barrett Energy Inc.
             (formerly known as Vanilla Corporation) and Plains Petroleum
             Company ("Plains"), (incorporated by reference to Annex I to the 
             Joint Proxy Statement/Prospectus).
3.1          Form of Certificate of Amendment to the Certificate of
             Incorporation of Barrett.
3.2          Form of Restated Certificate of Incorporation of Barrett (giving
             effect to the Certificate of Amendment to the Certificate of
             Incorporation included in Exhibit 3.1).
3.3          By-laws of Barrett, as amended.
5.1          Opinion of Simpson Thacher & Bartlett, regarding the legality of
             the securities to be offered.
5.2          Opinion of Bearman Talesnick & Clowdus Professional Corporation,
             regarding the legality of the securities to be offered.
8.1          Opinion of Simpson Thacher & Bartlett, regarding certain tax
             matters.
8.2          Opinion of Sidley & Austin, regarding certain tax matters.
21.1         Subsidiaries of Barrett (incorporated by reference to Barrett's
             Annual Report on Form 10-K for the year ended September 30, 1990).
23.1         Consent of Arthur Andersen LLP, independent accountants for each
             of Barrett and Plains.
23.2         Consent of Simpson Thacher & Bartlett (included in Exhibits 5.1
             and 8.1).
23.3         Consent of Bearman Talesnick & Clowdus Professional Corporation
             (included in Exhibit 5.2).
23.4         Consent of Sidley & Austin (included in Exhibit 8.2).
23.5         Consent of Ryder Scott Company.
23.6         Consent of Netherland, Sewell & Associates, Inc.
24.1         Powers of Attorney (included on the signature page hereto).
99.1         Form of Proxy of Barrett.
99.2         Form of Proxy of Plains.
99.3         Letter of Ryder Scott Company with respect to reserves of Barrett 
             as of September 30, 1994.
99.4         Letter of Ryder Scott Company with respect to reserves of Barrett
             as of March 31, 1995.
</TABLE>

Item 22.  Undertakings

     The undersigned registrant hereby undertakes:

     (1)  to file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

       (i) To include any prospectus required by Section 10(a)(3) of the
           Securities Act of 1933;

      (ii) To reflect in the prospectus any facts or events arising after the
           effective date of the registration statement (or the most recent 
           post-effective amendment thereof) which, individually or in the
           aggregate, represent a fundamental change in the information set
           forth in the registration statement;

     (iii) To include any material information with respect to the plan of
           distribution not previously disclosed in the registration statement
           or any material change to such information in the registration 
           statement;

                                     II-2
<PAGE>
 
     (2) That, for the purpose of determining any liability under the Securities
Act of 1933, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.

     The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to section 13(a) or section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in this
registration statement shall be deemed to be a new registration statement
relating to the securities offered herein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     The undersigned registrant hereby undertakes as follows: that prior to any
public reoffering of the securities registered hereunder through the use of a
prospectus which is a part of this Registration Statement, by any person or
party who is deemed to be an underwriter within the meaning of Rule 145(c), such
reoffering prospectus will contain the information called for by the applicable
registration form with respect to reofferings by persons who may be deemed
underwriters, in addition to the information called for by the other Items of
the applicable form.

     The undersigned registrant undertakes that every prospectus (i) that is
filed pursuant to the paragraph immediately preceding, or (ii) that purports to
meet the requirements of Section 10(a)(3) of the Securities Act of 1933 and is
used in connection with an offering of securities subject to Rule 415, will be
filed as a part of an amendment to the registration statement and will not be
used until such amendment is effective, and that. for purposes of determining
any liability under the Securities Act of 1933, each such post-effective
amendment shall be deemed to be a new registration statement relating to the
securities offered therein, and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

     The undersigned registrant hereby undertakes to respond to requests for
information that is incorporated by reference into the prospectus pursuant to
Items 4, 10(b), 11 or 13 of this form, within one business day of receipt of
such request. and to send the incorporated documents by first class mail or
other equally prompt means. This includes information contained in documents
filed subsequent to the effective date of the registration statement through the
date of responding to the request.

     The undersigned registrant hereby undertakes to supply by means of a post-
effective amendment all information concerning a transaction, and the company
being acquired involved therein, that was not the subject of and included in the
registration statement when it became effective.

                                     II-3
<PAGE>
 
                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
has caused this Registration Statement to be signed on its behalf by the
undersigned thereunto duly authorized, in the City of Denver, State of Colorado,
on June 9, 1995.

                            Barrett Resources Corporation


                            By:/s/ William J. Barrett
                               ----------------------
                               William J. Barrett
                               Chairman of the Board and Chief Executive Officer

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities indicated on June 9, 1995.

     Each person signing below also hereby appoints John F. Keller and Donald H.
Stevens, and each of them singly, his or her lawful attorney-in-fact with full
power to execute and file any amendments (including any post-effective
amendments) to the Registration Statement, and generally to do all such things
as such attorney-in-fact may deem appropriate to enable the Registrant to comply
with the provisions of the Securities Act of 1933 and all requirements of the
Securities and Exchange Commission.

<TABLE>
<CAPTION>
           Signature                               Title
           ---------                               -----                  
<S>                              <C>

 
 /s/ William J. Barrett          Chairman of the Board and Chief Executive
- -------------------------------    Officer (principal executive officer)
 William J. Barrett              
 
 
 /s/ Robert W. Howard            Senior Vice President--Finance and
- -------------------------------    Treasurer (principal financial
Robert W. Howard                   officer and principal accounting
                                   officer)
 
 
                                 Director
- -------------------------------
C. Robert Buford
 
 
                                 Director
- -------------------------------
James M. Fitzgibbons
 
 
                                 Director
- -------------------------------
Hennie L.J.M. Gieskes
</TABLE> 

                                     II-4
<PAGE>
 
<TABLE>
<CAPTION>
           Signature                               Title
           ---------                               -----                  
<S>                              <C>


 /s/ John F. Keller              Director
- -------------------------------
John F. Keller
 
 
 /s/ Paul M. Rady                Director
- -------------------------------
Paul M. Rady
 
 
 /s/ A. Ralph Reed               Director
- -------------------------------
A. Ralph Reed
 
 
                                 Director
- -------------------------------
James T. Rodgers
 
 /s/ Philippe S. E. Schreiber    Director
- -------------------------------
Philippe S.E. Schreiber
 
</TABLE>


                                     II-5
<PAGE>
 
                                 EXHIBIT INDEX
<TABLE>
<CAPTION>
 
 
Exhibit No.                           Description                           Page
- -----------                           -----------                           ----
<C>          <S>                                                            <C>
2.1          Agreement and Plan of Merger, dated as of May 2, 1995, among
             Barrett Resources Corporation ("Barrett"), Barrett Energy
             Inc. (formerly known as Vanilla Corporation) and Plains
             Petroleum Company ("Plains")(incorporated by reference to 
             Annex I to the Joint Proxy Statement/Prospectus).
3.1          Form of Certificate of Amendment to the Certificate of
             Incorporation of Barrett.
3.2          Form of Restated Certificate of Incorporation of Barrett
             (giving effect to the Certificate of Amendment to the
             Certificate of Incorporation included in Exhibit 3.1).
3.3          By-laws of Barrett, as amended.
5.1          Opinion of Simpson Thacher & Bartlett, regarding the
             legality of the securities to be offered.
5.2          Opinion of Bearman Talesnick & Clowdus Professional
             Corporation, regarding the legality of the securities to be
             offered.
8.1          Opinion of Simpson Thacher & Bartlett, regarding certain tax
             matters.
8.2          Opinion of Sidley & Austin, regarding certain tax matters.
21.1         Subsidiaries of Barrett (incorporated by reference to
             Barrett's Annual Report on Form 10-K for the year ended
             September 30, 1990).
23.1         Consent of Arthur Andersen LLP, independent accountants for
             each of Barrett and Plains.
23.2         Consent of Simpson Thacher & Bartlett (included in Exhibits
             5.1 and 8.1). 
23.3         Consent of Bearman Talesnick & Clowdus Professional
             Corporation (included in Exhibit 5.2).
23.4         Consent of Sidley & Austin (included in Exhibit 8.2).
23.5         Consent of Ryder Scott Company.
23.6         Consent of Netherland, Sewell & Associates, Inc.
24.1         Powers of Attorney (included on the signature page hereto).
99.1         Form of Proxy of Barrett.
99.2         Form of Proxy of Plains.
99.3         Letter of Ryder Scott Company with respect to reserves of 
             Barrett as of September 30, 1994.
99.4         Letter of Ryder Scott Company with respect to reserves of 
             Barrett as of March 31, 1995.          
</TABLE>
<PAGE>
 
                     GRAPHIC MATERIAL CROSS-REFERENCE PAGE


A MAP OF THE WESTERN UNITED STATES IDENTIFYING THE LOCATION OF THE AREAS OF
ACTIVITY OF BARRETT, OF PLAINS AND OF BOTH COMPANIES APPEARS ON PAGE 2.

<PAGE>
 
                                                                     EXHIBIT 3.1

                        CERTIFICATE OF AMENDMENT TO THE
                        CERTIFICATE OF INCORPORATION OF
                         BARRETT RESOURCES CORPORATION


Pursuant to the provisions of Section 242 of the General Corporation Law Of
Delaware, the undersigned corporation adopts the following amendment to its
Certificate Of Incorporation:

     FIRST:  The name of the corporation is Barrett Resources Corporation.

     SECOND:  The following amendment to the Certificate Of Incorporation was
adopted by a vote of the stockholders sufficient for approval effective on
________________________, 1995 in the manner prescribed by the General
Corporation Law of the State of Delaware:

          Article FOURTH of the Certificate Of Incorporation is amended to read
     in its entirety as follows:

               "FOURTH:  The total number of shares that the corporation shall
          have the authority to issue is 36,000,000, consisting of 35,000,000
          shares of common stock, with each share having a par value of $.01,
          and 1,000,000 shares of preferred stock, with each share having a par
          value of $.001.

                    The Board of Directors is hereby expressly authorized, by
          resolution or resolutions, to provide, out of the unissued shares of
          preferred stock, for the issuance of one or more series of preferred
          stock, with such voting powers, if any, and with such designations,
          preferences and relative, participating, optional or other special
          rights, and qualifications, limitations or restrictions thereof, as
          shall be expressed in the resolution or resolutions providing for the
          issuance thereof adopted by the Board of Directors, including, without
          limiting the generality of the foregoing, the following:

     (a)  the designation of such series, the number of shares to
          constitute such series and the stated value thereof if different
          from the par value thereof;

     (b)  whether the shares of such series shall have voting rights, in
          addition to any voting rights provided by law, and, if so, the
          terms of such voting rights, which may be general or limited;

     (c)  the dividends, if any, payable on such series, whether any such
          dividends shall be cumulative, and, if so, from what dates, the
          conditions and dates upon which such dividends shall be payable,
          the preference or relation which such dividends shall bear to the
<PAGE>
 
          dividends payable on any shares of stock of any other class or
          any other series of this class;

     (d)  whether the shares of such series shall be subject to redemption
          by the Corporation, and, if so, the times, prices and other terms
          and conditions of such redemption;

     (e)  the amount or amounts payable upon shares of such series upon,
          and the rights of the holders of such series in, the voluntary or
          involuntary liquidation, dissolution or winding up, or upon any
          distribution of the assets, of the Corporation;

     (f)  whether the shares of such series shall be subject to the
          operation of a retirement or sinking fund and, if so, the extent
          to and manner in which any such retirement or sinking fund shall
          be applied to the purchase or redemption of the shares of such
          series for retirement or other corporate purposes and the terms
          and provisions relative to the operation thereof;

     (g)  whether the shares of such series shall be convertible into, or
          exchangeable for, shares of stock of any other class or classes
          or of any other series of this class or any other class or
          classes of capital stock and, if so, the price or prices or the
          rate or rates of conversion or exchange and the method, if any,
          of adjusting the same, and any other terms and conditions of such
          conversion or exchange;

     (h)  the limitations and restrictions, if any, to be effective while
          any shares of such series are outstanding upon the payment of
          dividends or the making of other distributions on, and upon the
          purchase, redemption or other acquisition by the Corporation of,
          the common stock or shares of stock of any other class or any
          other series of this class; and

     (i)  the conditions or restrictions, if any, upon the creation of
          indebtedness of the Corporation or upon the issue of any
          additional stock, including additional shares of such series or
          of any other series of this class or of any other class or
          classes.

               The powers, preferences and relative, participating, optional and
               other special rights of each series of preferred stock, and the
               qualifications, limitations or restrictions thereof, if any, may
               differ from those of any and all other series at any time
               outstanding. All shares of any one series of preferred stock
               shall be identical in all respects with all other shares of such
               series, except that shares of any one series issued at different
               times may differ as to the dates from which dividends thereon
               shall be cumulative."
     
<PAGE>
 
     THIRD:  The Amendment does not provide for the exchange, reclassification
or cancellation of issued shares.

     FOURTH:  The Amendment does not effect a change in the amount of stated
capital.

     Dated:

ATTEST:                             BARRETT RESOURCES CORPORATION


__________________________________     By:_____________________________________
John F. Keller, Secretary                  William J. Barrett, President



     Each of the undersigned, William J. Barrett, the President of the
Corporation, and J. Frank Keller, the Secretary of the Corporation, hereby
affirms and acknowledges, under penalties of perjury, that the respective
signature of the undersigned on the foregoing instrument is his respective act
and deed or the act and deed of the Corporation, and that the facts stated in
the foregoing instrument are true.



                                    ________________________________________
                                    William J. Barrett, President



                                    ________________________________________
                                    John F. Keller, Secretary

<PAGE>
                                                                     EXHIBIT 3.2
 
                                    FORM OF
                                    RESTATED
                          CERTIFICATE OF INCORPORATION
                                       OF
                         BARRETT RESOURCES CORPORATION

     FIRST.  The name of the corporation is Barrett Resources Corporation.

     SECOND.   The address of the corporation's registered office is ______, 
______, Delaware ______. The name of its registered agent in the County of New
Castle is The Corporation Trust Company.

     THIRD.

          (a) The purpose of the corporation is to engage in any lawful act or
     activity for which a corporation may be organized under the General
     Corporation Law of Delaware (the "Delaware Code").

          (b) In furtherance of the foregoing purposes, the corporation shall
     have and may exercise all of the rights, powers and privileges granted by
     the Delaware Code.  In addition, it may do everything necessary, suitable
     and proper for the accomplishment of any of its corporate purposes.

     FOURTH.   The total number of shares that the corporation shall have the
authority to issue is 36,000,000 consisting of 35,000,000 shares of common
stock, with each share having a par value of $.01, and 1,000,000 shares of
preferred stock, with each share having a par value of $.001.

     The Board of Directors is hereby expressly authorized, by resolution or
resolutions, to provide, out of the unissued shares of preferred stock, for the
issuance of one or more series of preferred stock, with such voting powers, if
any, and with such designations, preferences and relative, participating,
optional or other special rights, and qualifications, limitations or
restrictions thereof, as shall be expressed in the resolution or resolutions
providing for the issuance thereof adopted by the Board of Directors, including,
without limiting the generality of the foregoing, the following:

          (a) the designation of such series, the number of shares to constitute
     such series and the stated value thereof if different from the par value
     thereof;

          (b) whether the shares of such series shall have voting rights, in
     addition to any voting rights provided by law, and, if so, the terms of
     such voting rights, which may be general or limited;

          (c) the dividends, if any, payable on such series, whether any such
     dividends shall be cumulative, and, if so, from what dates, the conditions
     and dates upon which such dividends shall be payable, the preference or
     relation which such dividends shall bear to the dividends payable on any
     shares of stock of any other class or any other series of this class;

          (d) whether the shares of such series shall be subject to redemption
     by the Corporation, and, if so, the times, prices and other terms and
     conditions of such redemption;
<PAGE>
 
          (e) the amount or amounts payable upon shares of such series upon, and
     the rights of the holders of such series in, the voluntary or involuntary
     liquidation, dissolution or winding up, or upon any distribution of the
     assets, of the Corporation;

          (f) whether the shares of such series shall be subject to the
     operation of a retirement or sinking fund and, if so, the extent to and
     manner in which any such retirement or sinking fund shall be applied to the
     purchase or redemption of the shares of such series for retirement or other
     corporate purposes and the terms and provisions relative to the operation
     thereof;

          (g) whether the shares of such series shall be convertible into, or
     exchangeable for, shares of stock of any other class or classes or of any
     other series of this class or any other class or classes of capital stock
     and, if so, the price or prices or the rate or rates of conversion or
     exchange and the method, if any, of adjusting the same, and any other terms
     and conditions of such conversion or exchange;

          (h) the limitations and restrictions, if any, to be effective while
     any shares of such series are outstanding upon the payment of dividends or
     the making of other distributions on, and upon the purchase, redemption or
     other acquisition by the Corporation of, the common stock or shares of
     stock of any other class or any other series of this class; and

          (i) the conditions or restrictions, if any, upon the creation of
     indebtedness of the Corporation or upon the issue of any additional stock,
     including additional shares of such series or of any other series of this
     class or of any other class or classes.

          The powers, preferences and relative, participating, optional and
     other special rights of each series of preferred stock, and the
     qualifications, limitations or restrictions thereof, if any, may differ
     from those of any and all other series at any time outstanding.  All shares
     of any one series of preferred stock shall be identical in all respects
     with all other shares of such series, except that shares of any one series
     issued at different times may differ as to the dates from which dividends
     thereon shall be cumulative.

     FIFTH.  The corporation is to have perpetual existence.

     SIXTH.    Whenever a compromise or arrangement is proposed between this
corporation and its creditors or any class of them and/or between this
corporation and its stockholders or any class of them, any court of equitable
jurisdiction within the State of Delaware may, on the application in a summary
way of this corporation or any creditor or stockholder thereof, or on the
application of any receiver or receivers appointed for this corporation under
the provisions of Section 291 of Title 8 of the Delaware Code or on the
application of trustees in dissolution or of any receiver or receivers appointed
for this corporation under the provisions of Section 279 of Title 8 of the
Delaware Code order a meeting of the creditors or class of creditors, and/or of
the stockholders or class of stockholders of this corporation, as the case may
be, to be summoned in such manner as the said court directs.  If a majority in
number representing three-fourths in value of the creditors or class of
creditors, and/or of the stockholders or class of stockholders of this
corporation, as the case may be, agree to any compromise or arrangement and to
any reorganization of this corporation as a consequence of such compromise or
arrangement, the said compromise or arrangement and the said reorganization
shall, if sanctioned by the court to which the said application has been made,
be binding on all the creditors or class of creditors,

                                       2
<PAGE>
 
and/or on all the stockholders or class of stockholders, of this corporation, as
the case may be, and also on this corporation.

     SEVENTH.  Each stockholder of record shall have one vote for each share of
stock standing in his or her name on the books of the corporation and entitled
to vote, except that in the election of directors he or she shall have the right
to vote such number of shares for as many persons as there are directors to be
elected.  Cumulative voting shall not be allowed in the election of directors or
for any other purpose.

     EIGHTH.   No stockholder of the corporation shall have any pre-emptive or
similar right to acquire any additional unissued or treasury shares of stock, or
other securities of any class, or rights, warrants or options to purchase stock
or scrip, or securities of any kind convertible into stock or carrying stock
purchase warrants or privileges.

     NINTH.    Elections of directors need not be by written ballot unless the
bylaws of the corporation so provide.

     TENTH.    The board of directors of the corporation is expressly authorized
to adopt, amend, or repeal the bylaws of the corporation.

     ELEVENTH. The following provisions are inserted for the management of the
business and for the conduct of the affairs of the corporation, and the same are
in furtherance of and not in limitation of the powers conferred by law:

          No contract or other transaction of the corporation with any other
     persons, firm or corporation, in which this corporation is interested,
     shall be affected or invalidated by the fact that any one or more of the
     directors or officers of this corporation, individually or jointly with
     others, may be a party to or may be interested in any such contract or
     transaction so long as the contract or other transaction is approved by the
     Board of Directors in accordance with the Delaware Code.  Each person who
     may become a director or officer of the corporation is hereby relieved from
     any liability that might otherwise arise by reason of his contracting with
     the corporation for the benefit of himself or any firm or corporation in
     which he may be in any way interested.

     TWELFTH.  The personal liability of each director of the Corporation shall
be eliminated and limited to the full extent permitted by the laws of the State
of Delaware, including without limitation as permitted by the provisions of
Section 102(b)(7) of the Delaware Code and any successor provision, as amended.

                                       3
<PAGE>
 
     THIRTEENTH.    The Corporation reserves the right to amend, alter, change
or repeal any provision contained in this certificate of incorporation, in the
manner now or hereafter prescribed by statute, and all rights conferred upon
stockholders herein are granted subject to this reservation.

     Dated this _______ day of _______, 1995.


 
                                                              --------------



STATE OF COLORADO          )
                           )
CITY AND COUNTY OF DENVER  )


     Before me, _____________________________, a Notary Public of the State of
Colorado, on the _____ of ________, 1995, personally appeared
____________________________, to me known and known to be the person who signed
the foregoing Restated Certificate Of Incorporation, who being duly sworn,
acknowledged that he signed, sealed and delivered the same as his voluntary act
and deed, for the uses and purposes therein expressed, and that the facts stated
therein are true.

                                                           
                                                      --------------------
                                                      Notary Public


     [SEAL]                                           Address:____________

                                                      --------------------
 


                              My Commission expires:  ____________________

                                       4

<PAGE>
 
                                                                     EXHIBIT 3.3

                                     BYLAWS



                                       OF



                         BARRETT RESOURCES CORPORATION



(As revised pursuant to a unanimous written Consent Of Directors effective as of
                                 May 15, 1995)
<PAGE>
 
                                     BYLAWS

                                       OF

                         BARRETT RESOURCES CORPORATION

                                   ARTICLE I.

                                    Offices
                                    -------

     The registered office of the corporation shall be in the City of
Wilmington, County of New Castle, State of Delaware or such other city and
county as the board of directors shall determine.

     The corporation may also have offices at such other places both within and
without the State of Delaware as the board of directors may from time to time
determine or the business of the corporation may require.

                                  ARTICLE II.

                                  Stockholders
                                  ------------

     Section 1.  Annual Meeting.  Beginning in 1988, the annual meeting of the
                 --------------                                               
stockholders shall be held at a time and date fixed by the board of directors
for the purpose of electing directors and for the transaction of such other
business as may come before the meeting.  If the election of directors shall not
be held at the annual meeting of the stockholders, or at any adjournment
thereof, the board of directors shall cause the election to be held at a special
meeting of the stockholders as soon thereafter as conveniently may be.

     Section 2.  Special Meetings.  Special meetings of the stockholders, for
                 ----------------                                            
any purpose, unless otherwise prescribed by statute, may be called by the
president or by the board of directors.

     Section 3.  Place Of Meeting.  The person or persons authorized to call any
                 ----------------                                               
annual or special meeting may designate any place, either within or outside
Delaware, as the place for the meeting.  A waiver of notice signed by all
stockholders entitled to vote at a meeting may designate any place, either
within or outside Delaware, as the place for such meeting.  If no designation is
made, the place of meeting shall be the principal corporate offices of the
corporation.

     Section 4.  Fixing Date For Determination Of Stockholders Of Record.  For
                 -------------------------------------------------------      
the purpose of determining stockholders entitled to notice of or to vote at any
meeting of stockholders or any adjournment thereof, or entitled to express
consent to corporate action in writing without a meeting, or entitled to receive
payment of any dividend or other distribution or allotment of any rights, or
entitled to exercise any rights in respect of any change, conversion or exchange
of stock or for any other lawful action, the board of directors may fix, in
advance, a date as the record date for any such determination of stockholders,
which date shall not be more than 60 nor less than ten days before the date of
such meeting, nor more than 60 days prior to any other action.  If no record
date is fixed then the record date shall be as follows:  (a) for determining
stockholders entitled to notice of or to vote at the meeting of stockholders,
the close of business on the day next preceding the day on which the meeting is
held; (b) for determining stockholders entitled to express consent to corporate
action in writing without a meeting, when no prior action by the board of
directors is necessary, the day on which the first written consent is expressed,
and (c) for determining stockholders for any other purpose, the close of
business on the day on which the board of directors adopts the resolution
relating thereto.  A determination of stockholders of record entitled to notice
of or to vote at a meeting of stockholders

                                       2
<PAGE>
 
shall apply to any adjournment of the meeting; provided, however, that the board
of directors may fix a new record date for the adjourned meeting.

     Section 5.  Notice Of Meeting.  Written notice stating the place, day and
                 -----------------                                            
hour of the meeting, and, in the case of a special meeting, the purpose or
purposes for which the meeting is called, shall be delivered not less than ten
nor more than 60 days before the date of the meeting, unless otherwise required
by statute, either personally or by mail, to each stockholder of record entitled
to vote at such meeting.  If mailed, such notice shall be deemed to be delivered
when deposited in the United States mail, addressed to the stockholder at his
address as it appears on the stock books of the corporation, with postage
thereon prepaid.  When a meeting is adjourned to another time or place, notice
need not be given of the adjourned meeting if the time and place thereof are
announced at the meeting at which the adjournment is taken.  At the adjourned
meeting the corporation may transact any business which might have been
transacted at the original meeting.

     Section 6.  Organization.  The president or any vice president shall call
                 ------------                                                 
meetings of stockholders to order and act as chairman of such meetings.  In the
absence of said officers, any stockholder entitled to vote at that meeting, or
any proxy of any such stockholder, may call the meeting to order and a chairman
shall be elected by a majority of the stockholders entitled to vote at that
meeting.  In the absence of the secretary or any assistant secretary of the
corporation, any person appointed by the chairman shall act as secretary of such
meetings.

     Section 7.  Agenda And Procedure.  The board of directors shall have the
                 --------------------                                        
responsibility of establishing an agenda for each meeting of stockholders,
subject to the rights of stockholders to raise matters for consideration which
may otherwise properly be brought before the meeting although not included
within the agenda.  The chairman shall be charged with the orderly conduct of
all meetings; provided however, that in the event of any difference in opinion
with respect to the proper cause of action which cannot be resolved by reference
to statute, or to the articles of incorporation or these bylaws, Robert's Rules
Of Order (as last revised) shall govern the disposition of the matter.

     Section 8.  Voting Lists.  The officer who has charge of the stock books of
                 ------------                                                   
the corporation shall prepare and make, at least ten days before every meeting
of stockholders, a complete list of the stockholders entitled to vote at the
meeting, arranged in alphabetical order, and showing the address of each
stockholder and the number of shares registered in the name of each stockholder.
Such list shall be open to the examination of each stockholder, for any purpose
germane to the meeting, during ordinary business hours, for a period of at least
ten days prior to the meeting, either at a place within the city where the
meeting is to be held, which place shall be specified in the notice of the
meeting, or if not so specified, at the place where the meeting is to be held.
The list shall also be produced and kept at the time and place of the meeting
during the whole time thereof, and may be inspected by any stockholder who is
present.

     Section 9.  Quorum.  The majority of the outstanding shares of the
                 ------                                                
corporation entitled to vote, represented in person or by proxy, shall
constitute a quorum at a meeting of stockholders for the transaction of business
except as otherwise provided by statute or the certificate of incorporation.  If
fewer than a majority of the outstanding shares are represented at a meeting, a
majority of the shares so represented may adjourn the meeting from time to time
in accordance with Section 5 of this Article II until a quorum shall be present
or represented.

     Section 10.  Manner Of Acting.  When a quorum is present at any meeting,
                  ----------------                                           
the affirmative vote of a majority of the shares represented at the meeting and
entitled to vote on the subject matter shall be the act of the stockholders,
unless a different vote is required by law or the certificate of incorporation,
in which case such express provision shall govern.


                                       3
<PAGE>
 
     Section 11.  Informal Action By Stockholders.  Unless otherwise provided in
                  -------------------------------                               
the certificate of incorporation, any action required or permitted to be taken
at any meeting of the stockholders may be taken without a meeting, without prior
notice and without a vote, provided that a consent in writing, setting forth the
action so taken, shall be signed by the holders of outstanding stock having not
less than the minimum number of votes that would be necessary to authorize or
take such action at a meeting at which all shares entitled to vote thereon were
present and voted.  Prompt notice of the taking of the corporate action without
a meeting by less than unanimous written consent shall be given to those
stockholders who have not consented in writing.  In the event that the action
which is consented to is such as would require the filing of a certificate with
the Secretary of State of Delaware under the General Corporation Law of the
State of Delaware if such action had been voted on by stockholders at a meeting
thereof, the certificate filed shall state, in lieu of any statement required
under law concerning any vote of stockholders, that written consent has been
given in accordance with the provision of law and that written notice has been
given as provided by law.

     Section 12.  Proxies.  Each stockholder entitled to vote at a meeting of
                  -------                                                    
stockholders or to express consent or dissent to corporate action in writing
without a meeting may authorize any other person or persons to act for him by
proxy, but no such proxy shall be voted or acted upon after three years from its
date unless the proxy provides for a longer period.

     Section 13.  Voting Of Shares.  Unless otherwise provided in the
                  ----------------                                   
certificate of incorporation and subject to the provisions of Section 4 of this
Article II, each stockholder shall be entitled to one vote for each share of
capital stock held by such stockholder.  In the election of directors, each
record holder of stock entitled to vote at such election shall have the right to
vote the number of shares owned by him for as many persons as there are
directors to be elected, and for whose election he has the right to vote.
Cumulative voting shall not be allowed.

     Section 14.  Voting Of Shares By Certain Holders.  Persons holding stock in
                  -----------------------------------                           
a fiduciary capacity shall be entitled to vote the shares so held.  Persons
whose stock is pledged shall be entitled to vote, unless in the transfer by the
pledgor on the books of the corporation the pledgor has expressly empowered the
pledgee to vote thereon, in which case only the pledgee or his proxy may
represent such shares and vote thereon.  If shares stand of record in the names
of two or more persons, whether fiduciaries, members of a partnership, joint
tenants, tenants in common, tenants by the entirety or otherwise, or if two or
more persons have the same fiduciary relationship respecting the same shares,
unless the secretary of the corporation is given written notice to the contrary
and if furnished with a copy of the instrument or order appointing them or
creating the relationship wherein it is so provided, their acts with respect to
voting shall be as set forth in the General Corporation Law of the State of
Delaware.

     Section 15.  Inspectors.  The chairman of the meeting may at any time
                  ----------                                              
appoint one or more inspectors to serve at a meeting of the stockholders.  Such
inspector(s) shall decide upon the qualifications of voters, including the
validity of proxies, accept and count the votes for and against the questions
presented, report the results of such votes, and subscribe and deliver to the
secretary of the meeting a certificate stating the number of shares of stock
issued and outstanding and entitled to vote thereon and the number of shares
voted for and against the questions presented.  The inspector(s) does not need
to be a stockholder of the corporation, and any director or officer of the
corporation may be an inspector on any question other than a vote for or against
his election to any position with the corporation or on any other question in
which he may be directly interested.

                                       4
<PAGE>
 
                                 ARTICLE III.

                               Board Of Directors
                               ------------------

     Section 1.  General Powers.  The business and affairs of the
                 --------------                                  
corporation shall be managed by or under the direction of its board of
directors, except as otherwise provided in the General Corporation Law of the
State of Delaware or the certificate of incorporation.

     Section 2.  Number, Tenure And Qualification.  The number of directors
                 --------------------------------                          
of the corporation shall be as determined by the board of directors and shall be
not fewer than three nor more than 13.  Directors shall be elected at each
annual meeting of stockholders except as otherwise provided in Section 3 of this
Article III or the certificate of incorporation.  Each director shall hold
office until his successor shall have been elected and qualified or until the
earliest of his death, resignation or removal.  Directors need not be residents
of Delaware or stockholders of the corporation.

     Any amendment or repeal of any provision or all provisions of this Article
III, Section 2, or the adoption of any provision inconsistent with any provision
or all provisions of this Article III, Section 2, shall, in addition to any
other vote or approval required by law or by these bylaws or by the certificate
of incorporation, require the affirmative vote of (a) at least 75 percent of all
the directors including at least two-thirds of the Independent Directors (as
defined in Article IV, Section 9 of these bylaws, together with other
capitalized terms used in Article III of these bylaws), or (b) (i) at least 66
2/3 percent of the outstanding shares of each class of Voting Stock, and (ii) at
least a majority, not including shares owned by Interested Persons, of the
outstanding shares of each class of Voting Stock.

     Section 3.  Notice Of Nominations.  Nominations for the election of
                 ---------------------                                  
directors may be made by the board of directors or a committee of the board of
directors or by any stockholder entitled to vote for the election of directors.
Nominations by the board of directors or a committee of the board of directors
may be made by oral or written notice delivered to the secretary of the
corporation by any officer or director on behalf of the board of directors or
committee at any time prior to or at any meeting of the stockholders at which
directors are to be elected.  Each notice of nomination of directors by the
board of directors or a committee of the board of directors shall set forth the
names of the nominees.  Nominations by stockholders shall be made by notice in
writing, delivered or mailed by first class United States mail, postage prepaid,
to the secretary of the corporation not less than 53 days nor more than 90 days
prior to any meeting of the stockholders at which directors are to be elected;
provided, however, that if less than 60 days' notice of the meeting is given to
stockholders, written notice of nominations of directors by stockholders shall
be delivered or mailed, as prescribed, to the secretary of the corporation not
later than the close of the seventh day following the day on which notice of the
meeting was mailed to stockholders.  Nominations by stockholders for directors
to be elected by written consent of stockholders shall be made by notice in
writing, delivered or mailed by first class United States mail, postage prepaid,
to the secretary of the corporation not less than 60 days nor more than 90 days
prior to the first solicitation of any written consents of stockholders for the
election of those nominees.  Each notice of nomination of directors by a
stockholder of the corporation shall set forth (a) the name, age, business
address and, if known, residence address of each nominee proposed in that
notice, (b) the principal occupation or employment of each such nominee for the
five years preceding the date of the notice, (c) the number of shares of stock
of the corporation that are beneficially owned by each nominee, and (d) any
arrangement, affiliation, association, agreement or other relationship of the
nominee with any stockholder of the corporation.  The chairman of any meeting of
stockholders of the corporation may, if the facts warrant, determine and declare
to the meeting that a nomination was not made in accordance with the foregoing
procedure, and if the chairman should so determine, the chairman shall so
declare to the meeting and the defective nomination shall be disregarded.

     Any amendment or repeal of any provision or all provisions of this
Article III, Section 3, or the adoption of any provision inconsistent with any
provision or all provisions of this Article III, Section 3,


                                       5
<PAGE>
 
shall, in addition to any other vote or approval required by law or by these
bylaws or by the certificate of incorporation, require the affirmative vote of
(a) at least 75 percent of all the directors including at least two-thirds of
the Independent Directors, or (b) (i) at least 66 2/3 percent of the outstanding
shares of each class of Voting Stock, and (ii) at least a majority, not
including shares owned by Interested Persons, of the outstanding shares of each
class of Voting Stock.

     Section 4.  Vacancies.  Any director may resign at any time by giving
                 ---------                                                
written notice to the corporation.  Such resignation shall take effect at the
time specified therein; and unless otherwise specified therein, the acceptance
of such resignation shall not be necessary to make it effective.  Any vacancy or
newly created directorship resulting from an increase in the authorized number
of directors may be filled by the affirmative vote of the majority of directors
then in office, although less than a quorum, or by a sole remaining director,
and a director so chosen shall hold office until the next annual election and
until his successor is duly elected and qualified, unless sooner displaced.  If
at any time, by reason of death, resignation or other cause, the corporation
should have no directors in office, then an election of directors may be held in
the manner provided by law.  When one or more directors shall resign from the
board, effective at a future date, a majority of the directors then in office,
including those who have so resigned, shall have the power to fill any vacancy
or vacancies, with the vote thereon to take effect when such resignation or
resignations shall become effective, and each director so chosen shall hold
office until the next annual election and until his successor is duly elected
and has qualified.

     Section 5.  Regular Meetings.  Unless otherwise approved by the board
                 ----------------                                         
of directors, a regular meeting of the board of directors shall be held without
other notice than this bylaw immediately after and at the same place as the
annual meeting of stockholders.  The board of directors may provide by
resolution the time and place, either within or outside Delaware, for the
holding of additional regular meetings without other notice than such
resolution.

     Section 6.   Special Meetings.  Special meetings of the board of
                  ----------------                                   
directors may be called by or at the request of the president or any two
directors.  The person or persons authorized to call special meetings of the
board of directors may fix any place, either within or outside Delaware, as the
place for holding any special meeting of the board of directors called by them.

     Section 7.  Notice.  Notice of any special meeting shall be given at
                 ------                                                  
least five days previously thereto by written notice delivered personally or
mailed to each director at his business address, or by notice given at least two
days previously thereto by telegraph.  If mailed, such notice shall be deemed to
be delivered when deposited in the United States mail so addressed, with postage
thereon prepaid.  If notice be given by telegram, such notice shall be deemed to
be delivered when the telegram is delivered to the telegraph company.  Neither
the business to be transacted at, nor the purpose of, any regular or special
meeting of the board of directors need be specified in the notice or waiver of
notice of such meeting.

     Section 8.  Quorum.  A majority of the number of directors then in
                 ------                                                
office shall constitute a quorum for the transaction of business at any meeting
of the board of directors, but if less than such majority is present at a
meeting, a majority of the directors present may adjourn the meeting from time
to time, without notice other than announcement at the meeting, until a quorum
shall be present.

     Section 9.  Manner Of Acting.  The vote of the majority of the
                 ----------------                                  
directors present at a meeting at which a quorum is present shall be the act of
the board of directors, except as may be otherwise specifically provided by law
or the certificate of incorporation.

     Section 10.  Removal.  Unless otherwise restricted by law, any
                  -------                                          
director or the entire board of directors may be removed, with or without cause,
by the holders of a majority of shares then entitled to vote at a meeting of
stockholders.

                                       6
<PAGE>
 
     Section 11.  Committees.  The board of directors may, by resolution
                  ----------                                            
passed by a majority of the whole board, designate one or more committees, each
committee to consist of one or more of the directors of the corporation.  The
board may designate one or more directors as alternate members of any committee,
who may replace any absent or disqualified member at any meeting of the
committee.  In the absence or disqualification of a member of a committee, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not they constitute a quorum, may unanimously appoint another
member of the board of directors to act at the meeting in the place of such
absent or disqualified member.  Any such committee, to the extent provided in
the resolution of the board of directors, shall have and may exercise all the
powers and authority of the board of directors in the management of the business
and affairs of the corporation, and may authorize the seal of the corporation to
be affixed to all papers which may require it; but no such committee shall have
the power or authority in reference to amend the certificate of incorporation,
to adopt an agreement of merger or consolidation, to recommend to the
stockholders the sale, lease or exchange of all or substantially all of the
corporation's property and assets, to recommend to the stockholders a
dissolution of the corporation or a revocation of a dissolution, or to amend the
bylaws of the corporation; and, unless the resolution expressly so provides, no
such committee shall have the power or authority to declare a dividend or to
authorize the issuance of stock.  Each committee shall keep regular minutes of
its meetings and report the same to the board of directors when required.

     Section 12.  Compensation.  Unless otherwise restricted by the
                  ------------                                     
certificate of incorporation or these bylaws, the board of directors shall have
the authority to fix the compensation of directors.  The directors may be paid
their expenses, if any, of attendance at such meeting of the board of directors
and may be paid a fixed sum for attendance at each meeting of the board of
directors or a stated salary as director.  No such payment shall preclude any
director from serving the corporation in any other capacity and receiving
compensation therefor.  Members of any committee of the board may be allowed
like compensation for attending committee meetings.

     Section 13.  Informal Action By Directors.  Unless otherwise
                  ----------------------------                   
restricted by the certificate of incorporation or these bylaws, any action
required or permitted to be taken at any meeting of the board of directors or
any committee thereof may be taken without a meeting if all members of the board
or committee, as the case may be, consent thereto in writing and the writing or
writings are filed with the minutes of the proceedings of the board or
committee.

     Section 14.  Meetings By Telephone.  Unless otherwise restricted by
                  ---------------------                                 
the certificate of incorporation or these bylaws, members of the board of
directors, or any committee designated by the board of directors, may
participate in a meeting of the board of directors, or any committee thereof, by
means of conference telephone or similar communications equipment by means of
which all persons participating in the meeting can hear each other, and such
participation in a meeting in such manner shall constitute presence in person at
the meeting.

                                  ARTICLE IV.

            Activities By, And Transactions With, Interested Persons
            --------------------------------------------------------

     Section 1.  No Acquisitions Of Additional Voting Stock.  After an
                 ------------------------------------------           
Interested Person (defined below together with other capitalized terms used in
this Article IV) has become an Interested Person, that Interested Person shall
not become the beneficial owner of any additional shares of Voting Stock except
as part of (a) the transaction that results in that Person first becoming an
Interested Person, or (b) pursuant to a Business Combination entered into in
accordance with the certificate of incorporation of the Corporation.

     Section 2.  Certain Events.  After any Interested Person has become an
                 --------------                                            
Interested Person, (a) there shall be no reduction in the annual rate of
dividends paid on the Common Stock (except as necessary to reflect any
subdivision of the Common Stock) without Independent Director Approval, and (b)
there shall

                                       7
<PAGE>
 
be an increase in such annual rate of dividends as necessary to reflect any
reclassification (including any reverse stock split), recapitalization,
reorganization or any similar transaction that has the effect of reducing the
number of shares of outstanding Common Stock, unless the failure to increase
such annual dividend rate receives Independent Director Approval.

     Section 3.  Certain Benefits.  After an Interested Person has become
                 ----------------                                        
an Interested Person, neither that Interested Person nor its Affiliates shall
receive the benefit, directly or indirectly (except proportionately as a
stockholder of the Corporation), of any loans, advances, guarantees, pledges or
other financial assistance or any tax credits or other tax advantages provided
by the Corporation, whether in anticipation of or in connection with a Business
Combination or otherwise, unless such benefit receives Independent Director
Approval.

     Section 4.  Board Decisions.  A vote by Independent Directors
                 ---------------                                  
sufficient to constitute Independent Director Approval shall be sufficient to
determine, for the purposes of this Article IV, on the basis of information
known to the board of directors, (a) the number of shares of Voting Stock
beneficially owned by any Person, (b) whether a Person is an Affiliate or
Associate of another, (c) whether a Person has an agreement, arrangement or
understanding with another as to any matter referred to in this Article IV, (d)
whether the assets subject to any Business Combination constitute a Substantial
Part of the assets of the Corporation or Subsidiary in question, or (e) any
factual matter relating to the applicability or effect of this Article IV.

     Section 5.  Board Demands.  A majority of the Independent Directors
                 -------------                                          
may demand that any Person (a "Potential Interested Person") who the majority of
the Independent Directors has reason to believe is an Interested Person or who
the majority of the Independent Directors believes holds of record Voting Stock
beneficially owned by any Interested Person supply the Corporation with complete
information as to (a) the record owner(s) of all shares beneficially owned by
that Potential Interested Person, (b) the beneficial owner(s) of all shares held
of record by that Potential Interested Person, (c) the number of, and class or
series of, shares beneficially owned by that Potential Interested Person and the
certificate number(s) of the stock certificate(s) evidencing such shares, (d)
the number of, and class or series of, shares held of record by that Potential
Interested Person and the certificate number(s) of the stock certificate(s)
evidencing such shares, and (e) any factual matter relating to the applicability
or effect of this Article IV as may be reasonably requested of that Potential
Interested Person.  Any Potential Interested Person requested to provide
information pursuant to this Article IV, Section 5 shall furnish that
information within ten days after receipt of that request.

     Section 6.  Binding Decisions.  Any determinations made by the board
                 -----------------                                       
of directors, or by the Independent Directors, as the case may be, pursuant to
this Article IV in good faith and on the basis of such information and
assistance as was then reasonably available for that purpose shall be conclusive
and binding upon the Corporation and its stockholders, including any Interested
Person.

    Section 7.  Waiver Of Provisions.  Any or all of the provisions of
                --------------------                                  
this Article IV, and their application to any or all Interested Persons or any
or all Business Combinations, may be waived in whole or in part by Independent
Director Approval.

     Section 8.  Amendment; Repeal.  Any amendment or repeal of any
                 -----------------                                 
provision or all provisions of this Article IV, or the adoption of any provision
inconsistent with any provision or all provisions of this Article IV, shall, in
addition to any other vote or approval required by law or by these bylaws or by
the certificate of incorporation, require the affirmative vote of (a) at least
75 percent of all the directors including at least two-thirds of the Independent
Directors, or (b) (i) at least 66 2/3 percent of the outstanding shares of each
class of Voting Stock, and (ii) at least a majority, not including shares owned
by Interested Persons, of the outstanding shares of each class of Voting Stock.


                                       8
<PAGE>
 
     Section 9.  Definitions.  For purposes of this Article IV (and of
                 -----------                                          
other Articles where specified in these bylaws) the following terms shall have
the meanings indicated:

  (i)    Affiliate. An "Affiliate" of a specified Person is a Person that
         directly, or indirectly through one or more intermediaries, controls,
         or is controlled by, or is under common control with, the Person
         specified.

  (ii)   Associate. "Associate", when used to indicate a relationship with any
         Person, means (A) any corporation or organization (other than the
         Corporation or a Subsidiary) of which such Person is an officer or
         partner or is, directly or indirectly, the beneficial owner of 10
         percent or more of any class of equity securities, (B) any trust or
         other estate in which such Person has a substantial beneficial interest
         or as to which such Person serves as trustee or in a similar fiduciary
         capacity, and (C) any relative or spouse of such Person, or any
         relative of such spouse, who has the same home as such Person or is an
         officer or director of any corporation controlling or controlled by
         such Person.

  (iii)  Beneficial Ownership.  "Beneficial Ownership" has the same
         meaning as in Rule 13d-3 under the Securities Exchange Act Of
         1934 (or any successor rule or statutory provision) or, if Rule
         13d-3 shall be rescinded and there shall be no successor rule or
         statutory provision thereto, pursuant to Rule 13d-3 as in effect
         on January 1, 1994.  A Person shall, in any event, also be deemed
         to be the "beneficial owner" of each of the following:

         (A)  any Voting Stock that such Person or any of its Affiliates
              or Associates beneficially owns, directly or indirectly;

         (B)  any Voting Stock that such Person or any of its Affiliates
              or Associates possesses (1) the right to acquire (whether
              such right is exercisable immediately or only after the
              passage of time), pursuant to any agreement, arrangement or
              understanding (excluding any agreement, arrangement or
              understanding with the Corporation to effect a Business
              Combination) or upon the exercise of conversion rights,
              exchange rights, warrants, or options, or otherwise, or (2)
              sole or shared voting or investment power with respect to
              such Voting Stock pursuant to any agreement, arrangement,
              understanding, relationship or otherwise (excluding any
              revocable proxies granted for a particular meeting with
              respect to shares of which neither such Person nor any such
              Affiliate or Associate is otherwise deemed the beneficial
              owner); or

         (C)  any Voting Stock that is beneficially owned, directly or
              indirectly, by any other Person with which such first
              mentioned Person or any of its Affiliates or Associates acts
              as a partnership, limited partnership, syndicate or other
              group pursuant to any agreement, arrangement or
              understanding for the purpose of acquiring, holding, voting
              or disposing of any shares of capital stock of the
              Corporation.

          No director or officer of the Corporation, nor any Associate or
          Affiliate of any such director or officer, shall, solely by
          reason of any or all of such directors and officers acting in
          their capacities as such, be deemed to beneficially own any
          Voting Stock beneficially owned by any other such director or
          officer (or any Associate or Affiliate

                                       9
<PAGE>
 
          of any such director or officer).  No employee stock ownership or
          similar plan of the Corporation or any Subsidiary or any trustee
          of such a plan, nor any Associate or Affiliate of any such
          trustee, shall, solely by reason of such capacity of such
          trustee, be deemed to beneficially own any Voting Stock held
          under any such plan.

          To compute the percentage beneficial ownership of Voting Stock of a
          Person in order to determine if such Person is an Interested Person,
          the outstanding Voting Stock shall include shares deemed owned by such
          Person through application of Section 9(iii)(B) of this Article IV,
          and any other Voting Stock that may be issuable by the Corporation
          pursuant to any agreement, or upon the exercise of conversion rights,
          warrants or options, or otherwise. For all other purposes, the
          outstanding Voting Stock shall include only Voting Stock then
          outstanding.

     (iv) Business Combination.  "Business Combination" means any of the
          following:

          (A)  Merger.  Any merger or consolidation of the Corporation or
               ------                                                    
               any Subsidiary with or into (1) any Interested Person or any
               Affiliate of an Interested Person or (2) any other corporation,
               limited partnership, limited liability company or other entity
               (regardless of whether it is itself an Interested Person) if,
               after such merger or consolidation, the surviving or resulting
               entity would be an Affiliate of an Interested Person.

          (B)  Sale, Etc.  Any sale, lease, exchange, mortgage, pledge,
               ----------                                              
               transfer or other disposition (in one transaction or a series of
               related transactions) to or with any Interested Person or
               Affiliate of an Interested Person of any Substantial Part of the
               assets of the Corporation or any Subsidiary.

          (C)  Issuance Of Equity Securities.  The issuance or transfer by
               -----------------------------                              
               the Corporation or by a Subsidiary (in one transaction or a
               series of related transactions) of any Equity Securities of
               the Corporation or any Subsidiary to any Interested Person
               or Affiliate of an Interested Person except for (1) the
               exercise, exchange or conversion of securities exercisable
               or exchangeable for or convertible into such stock that were
               beneficially owned by that Person before it became an
               Interested Person or (2) a dividend, distribution, exchange
               or conversion of securities that does not result in an
               increase in the proportionate share beneficially owned by
               that Interested Person of any class or series of stock of
               the Corporation or any Subsidiary.

          (D)  Plan Of Liquidation.  The adoption of any plan or proposal
               -------------------                                       
               to liquidate or dissolve the Corporation if, as of the
               record date for the determination of stockholders entitled
               to notice of and to vote on the plan or proposal, any Person
               is an Interested Person.

          (E)  Reclassification.  Any reclassification of securities
               ----------------                                     
               (including any reverse stock split) or recapitalization of
               the Corporation, or any reorganization, merger or
               consolidation of the Corporation with any of its
               Subsidiaries or any similar transaction (regardless of
               whether the transaction is with or into or otherwise
               involving an Interested Person) that has the effect,
               directly or indirectly, of increasing the percentage
               beneficially owned by any Interested Person of any class of
               Equity Securities of the Corporation or any Subsidiary,
               except as a result of immaterial changes due to fractional
               share adjustments.

                                      10
<PAGE>
 
           (v)   Corporation.  The "Corporation" means Barrett Resources 
                 Corporation.

           (vi)  Equity Security. "Equity Security" means any stock or similar
                 security, certificate of interest or participation in any
                 profit sharing agreement, preorganization certificate or
                 subscription, transferable share, voting trust certificate or
                 certificate of deposit for an equity security, limited
                 partnership interest, interest in a joint venture, or
                 certificate of interest in a business trust; or any security
                 convertible with or without consideration into such a security,
                 or carrying any warrant or right to subscribe to or purchase
                 such a security; or any such warrant or right; or any put,
                 call, straddle, or other option or privilege of buying such a
                 security from or selling such a security to another without
                 being bound to do so.

          (vii)  Independent Director. "Independent Director" means any member
                 of the board of directors of the Corporation who is not an
                 employee of the Corporation or any Subsidiary and who is not an
                 Affiliate or Associate of, and not a nominee of, either (1) an
                 Interested Person who is an Interested Person with respect to a
                 Business Combination that has been proposed during the two-year
                 period preceding the date of the action in question, or an
                 Affiliate of such Interested Person, or (2) an Interested
                 Person involved in a transaction, matter, or other proposal
                 that is the subject of a vote of the board of directors or a
                 committee of the board of directors for which a determination
                 of Independent Director status is being made, or an Affiliate
                 of such Interested Person.

          (viii) Independent Director Approval. "Independent Director Approval"
                 means approval by at least two-thirds of the Independent
                 Directors at a time when the number of Independent Directors is
                 at least equal to two-thirds of the number of Independent
                 Directors immediately before the Interested Person became an
                 Interested Person.

          (ix)   Interested Person. "Interested Person" means any Person (other
                 than the Corporation or any Subsidiary) who or which, as of any
                 particular date, is the beneficial owner, directly or
                 indirectly, of more than 15 percent of the outstanding shares
                 of any single class, or of all classes in the aggregate, of
                 Voting Stock.

          (x)    Person.  "Person" means any individual or entity.

          (xi)   Subsidiary.  "Subsidiary" means any corporation of which a
                 majority of any class of equity security is owned, directly or
                 indirectly, by the Corporation, except that for the purposes of
                 the definition of Interested Person the term "Subsidiary" means
                 only a corporation of which a majority of each class of equity
                 security is owned, directly or indirectly, by the Corporation.

          (xii)  Substantial Part. "Substantial Part" means assets having a book
                 value in excess of 20 percent of the book value of the total
                 consolidated assets of the Corporation (or Subsidiary, if
                 applicable) (determined in according with generally accepted
                 accounting principles), at the end of its most recent fiscal
                 year ending before the determination is made.

          (xiii) Voting Stock.  "Voting Stock" means outstanding shares of
                 capital stock generally entitled to vote in the election of
                 directors, or, with respect to any particular matter, generally
                 entitled to vote on that matter.


                                      11
<PAGE>
 
     Section 10.  Severability.  If any provision (or portion thereof) of this
                  ------------                                                
Article IV is found to be invalid, prohibited or unenforceable for any reason,
the remaining provisions (or portions thereof) of this Article IV shall be
deemed to remain in full force and effect and shall be construed as if such
invalid, prohibited or unenforceable provision had been stricken herefrom or
otherwise rendered inapplicable, it being the intent of the Corporation and its
stockholders that each such remaining provision (or portion thereof) of this
Article IV remain, to the fullest extent permitted by law, applicable and
enforceable as to all stockholders, including Interested Persons,
notwithstanding any such finding.

                                   ARTICLE V.

                              Officers And Agents
                              -------------------

     Section 1.  General.  The officers of the corporation shall be a president,
                 -------                                                        
a secretary and a treasurer.  The board of directors may appoint such other
officers, assistant officers, and agents, a chairman or vice-chairmen of the
board, assistant secretaries and assistant treasurers, as they may consider
necessary, who shall be chosen in such manner and hold their offices for such
terms and have such authority and duties as from time to time may be determined
by the board of directors.  The salaries of all the officers of the corporation
shall be fixed by the board of directors.  Any number of offices may be held by
the same person with the exception of the office of president and secretary
being held simultaneously by the same person, or as otherwise provided in the
certificate of incorporation or these bylaws.

     Section 2.  Election And Term Of Office.  The officers of the corporation
                 ---------------------------                                  
shall be elected by the board of directors annually at the first meeting of the
board held after each annual meeting of the stockholders.  If the election of
officers shall not be held at such meeting, such election shall be held as soon
thereafter as conveniently may be.  Each officer shall hold office until his
successor shall have been duly elected and qualified or until the earliest to
occur of his death, resignation or removal.

     Section 3.  Removal.  Any officer or agent elected or appointed by the
                 -------                                                   
board of directors may be removed at any time by the board whenever in its
judgment the best interests of the corporation will be served thereby.

     Section 4.  Vacancies.  Any officer may resign at any time upon written
                 ---------                                                  
notice to the corporation.  Such resignation shall take effect at the time
stated therein; and unless otherwise specified therein, the acceptance of such
resignation shall not be necessary to make it effective.  Any vacancy occurring
in any office by death, resignation, removal or otherwise shall be filled by the
board of directors for the unexpired portion of the term.  If any officer shall
be absent or unable for any reason to perform his duties, the board of
directors, to the extent not otherwise consistent with these bylaws or law, may
direct that the duties of such officer during such absence or inability shall be
performed by such other officer or assistant officer as seems advisable to the
board.

     Section 5.  Authority And Duties Of Officers.  The officers of the
                 --------------------------------                      
corporation shall have the authority and shall exercise the powers and perform
the duties specified below, and as may be otherwise specified by the board of
directors or by these bylaws, except that in any event each officer shall
exercise such powers and perform such duties as may be required by law, and in
cases where the duties of any officer or agent are not prescribed by these
bylaws or by the board of directors, such officer or agent shall follow the
orders and instructions of (a) the president, and if a chairman of the board is
elected, then (b) the chairman of the board.

          (a)   President.  The president, subject to the direction and
                ---------                                              
supervision of the board of directors, shall have the following
responsibilities:  (i) be the chief executive officer of the corporation and
have general and active control of its affairs, business and property and
general supervision of its officers, agents and employees; (ii) preside at all
meetings of the stockholders; (iii) see that all orders and resolutions


                                      12
<PAGE>
 
of the board of directors are carried into effect; and (iv) sign or countersign
all certificates, contracts and other instruments of the corporation, except
where required or permitted by law to be otherwise signed and executed and
except where the signing and execution thereof shall be expressly delegated by
the board of directors to some other officer or agent of the corporation.  In
addition, the president shall, unless otherwise directed by the board of
directors, attend in person or by substitute appointed by them, or by written
instruments appointing proxy or proxies to represent the corporation, all
meetings of the stockholders of any corporation in which the corporation shall
hold any stock and may, on behalf of the corporation, in person or by substitute
or proxy, execute written waivers of notice and consents with respect to such
meetings.  At all such meetings, and otherwise, the president, in person or by
substitute or proxy as aforesaid, may vote the stock so held by the corporation
and may execute written consent and other instruments with respect to such stock
and may exercise any and all rights and powers incident to the ownership of said
stock, subject however to the instructions, if any, of the board of directors.
Subject to the directions of the board of directors, the president shall
exercise all other powers and perform all other duties normally incident to the
office of president of a corporation and shall exercise such other powers and
perform such other duties as from time to time may be assigned to him by the
board.  If a chairman of the board has been elected, the chairman of the board
shall have, subject to the direction and modification of the board of directors,
all the same responsibilities, rights and obligations as described in these
bylaws for the president.

          (b)   Vice Presidents.  The vice presidents, if any shall be elected,
                ---------------                                                
and if they be so directed shall assist the president and shall perform such
duties as may be assigned to them by the president or by the board of directors.
In the absence of the president, the vice president designated by the board of
directors or (if there be no such designation) designated in writing by the
president shall have the powers and perform the duties of the president.  If no
such designation shall be made all vice presidents may exercise such powers and
perform such duties.

          (c)   Secretary.  The secretary shall perform the following functions:
                ---------            
(i)  record or cause to be recorded the proceedings of the meeting of the
stockholders, the board of directors and any committees of the board of
directors in a book to be kept for that purpose; (ii) see that all notices are
duly given in accordance with the provisions of these bylaws or as required by
law; (iii)  be custodian of the corporate records and of the seal of the
corporation; (iv) keep at the corporation's registered office or principal place
of business within or outside Delaware a record containing the names and
addresses of all stockholders and the number and class of shares held by each,
unless such a record shall be kept at the office of the corporation's transfer
agent or registrar; (v) have general charge of the stock books of the
corporation, unless the corporation has a transfer agent; and (vi) in general,
perform all other duties as from time to time may be assigned to him by the
president, or by the board of directors.  Assistant secretaries, if any, shall
have the same duties and powers, subject to supervision by the secretary.

          (d)   Treasurer.  The treasurer shall perform the following functions:
                ---------            
(i) be the principal financial officer of the corporation and have the care and
custody of all funds, securities, evidences of indebtedness and other personal
property of the corporation and deposit the same in accordance with the
instructions of the board of directors; (ii) receive and give receipts and
acquittances for monies paid in on account of the corporation, and pay out of
the funds on hand all bills, payrolls and other just debts of the corporation of
whatever nature upon maturity; (iii) be the principal accounting officer of the
corporation and as such prescribe and maintain the methods and systems of
accounting to be followed, keep complete books and records of account, prepare
and file all local, state and federal tax returns, prescribe and maintain an
adequate system of internal audit, and prepare and furnish to the president and
the board of directors statements of account showing the financial position of
the corporation and the results of its operations; and (iv) perform all other
duties incident to the office of treasurer and such other duties as from time to
time may be assigned to him by the president or the board of directors.
Assistant treasurers, if any, shall have the same powers and duties, subject to
the supervision of the treasurer.

                                      13
<PAGE>
 
     Section 6.  Surety Bonds.  The board of directors may require any
                 ------------                                         
officer or agent of the corporation to execute to the corporation a bond in such
sums and with such sureties as shall be satisfactory to the board, conditioned
upon the faithful performance of his duties and for the restoration to the
corporation of all books, papers, vouchers, money and other property of whatever
kind in his possession or under his control belonging to the corporation.

     Section 7.  Salaries.  Officers of the corporation shall be entitled
                 --------                                                
to such salaries, emoluments, compensation or reimbursement as shall be fixed or
allowed from time to time by the board of directors.

                                  ARTICLE VI.

                                     Stock
                                     -----

     Section 1.  Certificates.  Each holder of stock in the corporation
                 ------------                                          
shall be entitled to have a certificate signed in the name of the corporation by
the president or a vice-president, and by the treasurer or an assistant
treasurer, or the secretary or an assistant secretary of the corporation.  Any
of or all the signatures on the certificate may be facsimile.  In case any
officer, transfer agent or registrar who has signed or whose facsimile signature
has been placed upon a certificate shall have ceased to be such officer,
transfer agent or registrar before such certificate is issued, it may be issued
by the corporation with the same effect as if he were such officer, transfer
agent or registrar at the date of issue.  Certificates of stock shall be
consecutively numbered and shall be in such form consistent with law as shall be
prescribed by the board of directors.

     Section 2.   Record.  A record shall be kept of the name of each
                  ------                                             
person or other entity holding the stock represented by each certificate for
shares of the corporation issued, the number of shares represented by each such
certificate, the date thereof and, in the case of cancellation, the date of
cancellation.  The person or other entity in whose name shares of stock stand on
the books of the corporation shall be deemed the owner thereof, and thus a
holder of record of such shares of stock, for all purposes as regards the
corporation.

     Section 3.   Consideration For Shares.  Shares shall be issued for
                  ------------------------                             
such consideration (but not less than the par value thereof) as shall be
determined from time to time by the board of directors.  Treasury shares shall
be disposed of for such consideration as may be determined from time to time by
the board.  Such consideration may consist, in whole or in part, of cash,
personal property, real property, leases of real property, services rendered, or
promissory notes, and shall be paid in such form, in such manner and at such
times as the directors may require.

     Section 4.  Issuance of Stock.  The capital stock issued by the
                 -----------------                                  
corporation shall be deemed to be fully paid and nonassessable stock, if: (a)
the entire amount of the consideration has been received by the corporation in
the form or forms set forth in Section 3 of this Article VI and if any part of
the consideration is in the form of a promissory note or other obligation, such
note or obligation has been satisfied in full; or (b) not less than the amount
of the consideration determined to be capital pursuant to statute has been
received by the corporation in the form or forms set forth in Section 3 of this
Article VI and the corporation has received a binding obligation of the
subscriber or purchaser to pay the balance of the subscription or purchase
price; provided, however, nothing contained herein shall prevent the board of
directors from issuing partly paid shares as described herein.

     The corporation may issue the whole or any part of its shares as
partly paid and subject to call for the remainder of the consideration to be
paid therefor.  Upon the face or back of each stock certificate issued to
represent any such partly paid shares the total amount of the consideration to
be paid therefor and the amount paid thereon shall be stated.  Upon the
declaration of any dividend upon partly paid shares, the corporation shall
declare a dividend upon partly paid shares of the same class, but only upon the
basis of the percentage of the consideration actually paid thereon.

                                      14
<PAGE>
 
     The directors may from time to time demand payment, in respect of each
share of stock not fully paid, of such sum of money as the necessities of the
business may, in the judgment of the board of directors, require, not exceeding
in the whole, the balance remaining unpaid on said stock, and such sum so
demanded shall be paid to the corporation at such times and by such installments
as the directors shall direct.  The directors shall give written notice of the
time and place of such payments, which notice shall be mailed to each holder or
subscriber to his last known post office address at least thirty days before the
time for such payment for stock which is not fully paid.

     The corporation may, but shall not be required to, issue fractions of
a share.  If it does not issue fractions of a share, it shall: (a) arrange for
the disposition of fractional interests by those entitled thereto; (b) pay in
cash the fair value of fractions of a share as of the time when those entitled
to receive such fractions are determined; or (c) issue scrip or warrants in
registered or bearer form which shall entitle the holder to receive a
certificate for a full share upon the surrender of such scrip or warrants
aggregating a full share.  A certificate for a fractional share shall, but scrip
or warrants shall not unless provided therein, entitle the holder to exercise
voting rights, to receive dividends thereon, and to participate in any of the
assets of the corporation in the event of liquidation.  The board of directors
may cause scrip or warrants to be issued subject to the conditions that they
shall become void if not exchanged for certificates representing full shares
before a specified date, or subject to the conditions that the shares for which
scrip or warrants are exchangeable may be sold by the corporation and the
proceeds thereof distributed to the holders of scrip or warrants, or subject to
any other conditions which the board of directors may impose.

     The board of directors may, at any time and from time to time, if all
of the shares of capital stock which the corporation is authorized by its
certificate of incorporation to issue have not been issued, subscribed for, or
otherwise committed to be issued, issue or take subscriptions for additional
shares of its capital stock up to the amount authorized in its certificate of
incorporation.

     Section 5.  Lost Certificates.  In case of the alleged loss,
                 -----------------                               
destruction or mutilation of a certificate of stock, the board of directors may
direct the issuance of a new certificate in lieu thereof upon such terms and
conditions in conformity with law as it may prescribe.  The board of directors
may in its discretion require a bond in such form and amount and with such
surety as it may determine, before issuing a new certificate.

     Section 6.  Transfer Of Shares.  Upon surrender to the corporation or
                 ------------------                                       
to a transfer agent of the corporation of a certificate of stock duly endorsed
or accompanied by proper evidence of succession, assignment or authority to
transfer, it shall be the duty of the corporation to issue a new certificate to
the person entitled thereto, cancel the old certificate, and record the
transaction in the stock books.

     Section 7.  Registered Stockholders.  The corporation shall be
                 -----------------------                           
entitled to recognize the exclusive right of a person registered on its books as
the owner of shares to receive dividends, and to vote as such owner, and the
corporation shall be entitled to hold liable for calls and assessments a person
registered on its books as the owner of shares, and the corporation shall not be
bound to recognize any equitable or other claim to or interest in such share or
shares on the part of any other person, whether or not it shall have express or
other notice thereof except as otherwise provided by the laws of Delaware.

     Section 8.  Transfer Agents, Registrars And Paying Agents.  The board
                 ---------------------------------------------            
may at its discretion appoint one or more transfer agents, registrars and agents
for making payment upon any class of stock, bond, debenture or other security of
the corporation.  Such agents and registrars may be located either within or
outside Delaware.  They shall have such rights and duties and shall be entitled
to such compensation as may be agreed.


                                      15
<PAGE>
 
                                 ARTICLE VII.

                   Indemnification Of Officers And Directors
                   -----------------------------------------

     Section 1.  Indemnification Of Directors, Officers, And Others.  Any
                 --------------------------------------------------      
person who was or is a party or is threatened to be made a party to any
threatened, pending or completed action, suit or proceeding, whether civil,
criminal, administrative or investigative, by reason of the fact that he is or
was at any time since the inception of the corporation a director, officer or
employee of the corporation, or is or was at any time since the inception of the
corporation serving at the request of the corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise, including serving as trustee, plan administrator or other
fiduciary of any employee benefit plan, shall be indemnified by the corporation
to the full extent permitted by the General Corporation Law of the State of
Delaware (or any similar provision or provisions of applicable law at the time
in effect).

     Section 2.  Indemnification Of Officers, Directors And Employees
                 ----------------------------------------------------
Pursuant To The Common Law Or Statutory Provisions Other Than The General
- -------------------------------------------------------------------------
Corporation Law Of The State Of Delaware.  Any person who was or is a party or
- ----------------------------------------                                      
is threatened to be made a party to any threatened, pending or completed action,
suit or proceeding, whether civil, criminal, administrative or investigative, by
reason of the fact that he is or was at any time since the inception of the
corporation a director, officer or employee of the corporation, or is or was at
any time since the inception of the corporation serving at the request of the
corporation as a director, officer, or employee of another corporation,
partnership, joint venture, trust or other enterprise, including serving as
trustee, plan administrator or other fiduciary of any employee benefit plan,
shall be indemnified by the corporation to the full extent permitted by the
common law and by any statutory provision other than the General Corporation Law
of the State of Delaware.

     Section 3. Mandatory Advance Of Expenses.  Reasonable expenses
                -----------------------------                      
incurred in defending any action, suit or proceeding described in Section 1 or 2
of this Article VII shall be paid by the corporation in advance of the final
disposition of such action, suit or proceeding upon receipt of an undertaking by
or on behalf of such director, officer or employee to repay such amount to the
corporation if it shall ultimately be determined that he is not entitled to be
indemnified by the corporation as authorized in this Article VII.

     Section 4.  Payment Of Indemnified Claims.  Reasonable amounts
                 -----------------------------                     
required to be paid in settlement or as a judgment in any action, suit or
proceeding described in Section 1 or 2 of this Article VII shall be paid by the
corporation within 90 days of the receipt of an undertaking by or on behalf of
such director, officer or employee to repay such amount to the corporation if it
shall ultimately be determined that he is not entitled to be indemnified by the
corporation as authorized in this Article VII; provided however, that the
corporation shall not be required to pay such amounts if a majority of the
members of the Board of Directors vote to deny the request for indemnification
within the 90 day period set forth in this Section 4 if such amounts previously
have not been paid by the corporation in accordance with this Section 4.

     Section 5.  Rights Of Appeal.  In the event that the corporation
                 ----------------                                    
advances funds for indemnification pursuant to this Article VII, and,
subsequently, indemnification pursuant to this Article VII is declared
unenforceable by a court, or the corporation determines that the director,
officer or employee on whose behalf the funds were advanced is not entitled to
indemnification pursuant to this Article VII, then such director, officer or
employee shall have the right to retain the indemnification payments until all
appeals of the court's or the corporation's decision have been exhausted.

     Section 6.  Additional Indemnification.  Without limiting the
                 --------------------------                       
indemnification otherwise provided by this Article VII, any person who was or is
a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative, by reason of the fact that he is or was at any time since the
inception of the corporation a director, officer or employee of the corporation
or a wholly owned subsidiary of the corporation, or is or was

                                      16
<PAGE>
 
at any time since the inception of the corporation a trustee, plan administrator
or other fiduciary of any employee benefit plan of the corporation or a wholly
owned subsidiary of the corporation, shall be indemnified by the corporation
against all expenses, including attorneys' fees, judgments, fines and amounts
paid in settlement, actually and reasonably incurred by him in connection with
such action, suit or proceeding, including an action or suit by or in the right
of the corporation to procure a judgment in its favor, if he acted in good faith
and in a manner he reasonably believed to be in or not opposed to the best
interests of the corporation, and, with respect to any criminal action or
proceeding, he had no reasonable cause to believe his conduct was unlawful.  The
termination of any action, suit or proceeding by judgment, order, settlement,
conviction, or upon a plea of nolo contendere or its equivalent, shall not, of
itself, create a presumption that the person did not act in good faith and in a
manner which he reasonably believed to be in or not opposed to the best
interests of the corporation, and with respect to any criminal action or
proceeding, had reasonable cause to believe that his conduct was unlawful.

     Section 7.  Indemnification Not Exclusive.  The indemnification
                 -----------------------------                      
provided in this Article VII shall not be deemed exclusive of any other rights
to which any person seeking indemnification may be entitled under any agreement,
vote of stockholders or disinterested directors or otherwise, both as to action
in his official capacity and as to action in another capacity while holding such
office.

     Section 8.  Insurance.  By action of the board of directors,
                 ---------                                       
notwithstanding any interest of the directors in such action, the corporation
may purchase and maintain insurance, in such amounts as the board may deem
appropriate, on behalf of any person who is or was a director, officer or
employee of the corporation or is or was serving at the request of the
corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise against any liability
asserted against him and incurred by him in any such capacity, or arising out of
his status as such, whether or not the corporation would have the power to
indemnify him against such liability under applicable provisions of laws.

     Section 9.  Applicability; Effect.  Any indemnification and
                 ---------------------                          
advancement of expenses provided by or granted pursuant to this Article VII
shall be applicable to acts or omissions that occurred prior to the adoption of
this Article VII, shall continue as to any persons who ceased to be a director,
officer, or employee of the corporation or a wholly owned subsidiary of the
corporation, or was serving as or has since ceased to be a trustee, plan
administrator or other fiduciary of any employee benefit plan of the corporation
or a wholly owned subsidiary of the corporation, and shall inure to the benefit
of the heirs, executors, and administrators of such person.  The repeal or
amendment of this Article VII or any Section or provision thereof which would
have the effect of limiting, qualifying or restricting any of the powers or
rights of indemnification provided or permitted in this Article VII shall not,
solely by reason of such repeal or amendment, eliminate, restrict or otherwise
affect the right or power of the corporation to indemnify any person, or affect
any right of indemnification of such person, with respect to any acts or
omissions which occurred prior to such repeal or amendment.  All rights under
this Article VII shall be deemed to be provided by a contract between the
corporation and each person covered hereby.

     Section 10.  Savings Clause.  If this Article VII or any Section or
                  --------------                                        
provision hereof shall be invalidated by any court on any ground, then the
corporation shall nevertheless indemnify each party otherwise entitled to
indemnification hereunder to the fullest extent permitted by law or any
applicable provision of this Article VII that shall not have been invalidated.

                                 ARTICLE VIII.

                    Execution Of Instruments; Loans; Checks
                    ---------------------------------------
                      And Endorsements; Deposits; Proxies
                      -----------------------------------

     Section 1.  Execution Of Instruments.  The president or any vice
                 ------------------------                            
president shall have the power to execute and deliver on behalf of and in the
name of the corporation any instrument requiring the

                                      17
<PAGE>
 
signature of an officer of the corporation, except as otherwise provided in
these bylaws or where the execution and delivery thereof shall be expressly
delegated by the board of directors to some other officer or agent of the
corporation.  Unless authorized to do so by these bylaws or by the board of
directors, no officer, agent or employee shall have any power or authority to
bind the corporation in any way, to pledge its credit or to render it liable
pecuniarily for any purpose or in any amount.

     Section 2.  Loans To Directors, Officers And Employees.  The
                 ------------------------------------------      
corporation may lend money to, guarantee the obligations of and otherwise assist
directors, officers and employees of the corporation, or directors of another
corporation of which the corporation owns a majority of the voting stock, only
upon compliance with the requirements of the General Corporation Law of the
State of Delaware.

     Section 3.  Checks And Endorsements.  All checks, drafts or other
                 -----------------------                              
orders for the payment of money, obligations, notes or other evidences of
indebtedness, bills of lading, warehouse receipts, trade acceptances and other
such instruments shall be signed or endorsed by such officers or agents of the
corporation as shall from time to time be determined by resolution of the board
of directors, which resolution may provide for the use of facsimile signatures.

     Section 4.  Deposits.  All funds of the corporation not otherwise
                 --------                                             
employed shall be deposited from time to time to the corporation's credit in
such banks or other depositories as shall from time to time be determined by
resolution of the board of directors, which resolution may specify the officers
or agents of the corporation who shall have the power, and the manner in which
such powers shall be exercised, to make such deposits and to endorse, assign and
deliver for collection and deposit checks, drafts and other orders for the
payment of money payable to the corporation or its order.

     Section 5.  Proxies.  Unless otherwise provided by resolution adopted
                 -------                                                  
by the board of directors, the president or any vice president may from time to
time appoint one or more agents or attorneys-in-fact of the corporation, in the
name and on behalf of the corporation, to cast the votes which the corporation
may be entitled to cast as the holder of stock or other securities in any other
corporation, association or other entity any of whose stock or other securities
may be held by the corporation, at meetings of the holders of the stock or other
securities of such other corporation, association or other entity or to consent
in writing, in the name of the corporation as such other entity, and may
instruct the person or persons so appointed as to the manner of casting such
votes or giving such consent, and may execute or cause to be executed in the
name and on behalf of the corporation and under its corporate seal, or
otherwise, all such written proxies or other instruments as he may deem
necessary or proper in the premises.

                                  ARTICLE IX.

                                 Miscellaneous
                                 -------------

     Section 1.  Waivers Of Notice.  Whenever notice is required to be
                 -----------------                                    
given by law, by the certificate of incorporation or by these bylaws, a written
waiver thereof, signed by the person entitled to said notice, whether before or
after the time stated therein, shall be deemed equivalent to notice.  Attendance
of a person at a meeting or (in the case of a stockholder) by proxy shall
constitute a waiver of notice of such meeting, except when the person attends a
meeting for the express purpose of objecting, at the beginning of the meeting,
to the transaction of any business because the meeting was not lawfully called
or convened.  Neither the business to be transacted at, nor the purpose of, any
regular or special meeting of the stockholders, directors, or members of a
committee of directors need to be specified in any written waiver or notice
unless so required by the certificate of incorporation or these bylaws.

     Section 2.  Presumption Of Assent.  A director or stockholder of the
                 ---------------------                                   
corporation who is present at a meeting of the board of directors or
stockholders at which action on any corporate matter is taken shall be presumed
to have assented to the action taken unless his dissent shall be entered in the
minutes of


                                      18
<PAGE>
 
the meeting or unless he shall file his written dissent to such action with the
person acting as the secretary of the meeting before the adjournment thereof or
shall forward such dissent by registered mail to the secretary of the
corporation immediately after the adjournment of the meeting.  Such right to
dissent shall not apply to a director or stockholder who voted in favor of such
action.

     Section 3.  Seal.  The corporate seal of the corporation shall be
                 ----                                                 
circular in form and shall contain the name of the corporation and the words
"Seal, Delaware."  The custodian of the seal shall be the secretary, who along
with the president or other officer authorized by the board of directors, may
affix the seal to documents of the corporation.

     Section 4.  Amendments.  These bylaws may be altered, amended or
                 ----------                                          
repealed or new bylaws may be adopted by the board of directors or by the
stockholders in the manner provided in this Article IX, Section 4 at any
meeting, but not by written consent, of the stockholders.  In order for the
board of directors to effect an alteration, amendment or repeal of these bylaws
or to adopt new bylaws, written notice containing the proposed alteration,
amendment, repeal, or new bylaws must be provided to all the directors of the
corporation not less than 30 days prior to the meeting of directors at which the
proposal is to be considered unless the proposal is approved by at least 75
percent of all directors including 80 percent of Independent Directors (as
defined in Article IV, Section 9 of these bylaws together with other capitalized
terms used in Article IX of these bylaws).  In order for the stockholders to
effect an alteration, amendment, or repeal of these bylaws or to adopt new
bylaws, written notice containing the proposed alteration, amendment, repeal, or
new bylaws has been provided to the secretary and all the directors of the
corporation not more than seven days after the corporation gives notice of the
meeting of stockholders at which the proposal is to be considered.

    Any amendment or repeal of any provision or all provisions of this Article
IX, Section 4, or the adoption of any provision inconsistent with any provision
or all provisions of this Article IX, Section 4, shall, in addition to any other
vote or approval required by law or by these bylaws or by the certificate of
incorporation, require the affirmative vote of (a) at least 75 percent of all
the directors including at least two-thirds of the Independent Directors, or (b)
(i) at least 66 2/3 percent of the outstanding shares of each class of Voting
Stock, as defined in Article IV, Section 9 of these bylaws, and (ii) at least a
majority, not including shares owned by Interested Persons, of the outstanding
shares of each class of Voting Stock.

     Section 5.  Emergency Bylaws.  Subject to repeal or change by action
                 ----------------                                        
of the stockholders, the board of directors may adopt emergency bylaws in
accordance with and pursuant to the provisions of the General Corporation Law of
the State of Delaware.

                                   * * * * *



                                      19

<PAGE>
 
                                                                     EXHIBIT 5.1


                  [Letterhead of Simpson Thacher & Bartlett]

                                 June 9, 1995


Barrett Resources Corporation
1125 Seventeenth Street
Suite 2400
Denver, Colorado 80202

Dear Sirs:

        We have acted as special counsel to Barrett Resources Corporation, a
Delaware corporation (the "Company"), in connection with the proposed issuance
of shares of Common Stock, par value $.01 per share ("Common Stock"), of the
Company, in connection with the Agreement and Plan of Merger dated as of May 2,
1995 (the "Merger Agreement") among the Company, Barrett Energy Inc. (formerly
named Vanilla Corporation) ("Barrett Energy") and Plains Petroleum Company
("Plains").  Following a special meeting of stockholders of the Company at which
such stockholders will be asked to approve, among other things, an amendment to
the Company's Certificate of Incorporation to increase the Company's authorized
Common Stock to 35 million shares (the "Charter Amendment") and subject to
receipt of such approval and satisfaction or waiver of the other conditions to
the Merger set forth in the Merger Agreement, Barrett Energy will be merged with
and into Plains (the "Merger") and each outstanding share of common stock of
Plains will be converted into 1.3 shares of the Common Stock (in the aggregate,
the "Shares"), all as
<PAGE>
 
Barrett Resources Corporation                                       June 9, 1995


more fully described in the Registration Statement on Form S-4 (the
"Registration Statement") filed by the Company with the Securities and Exchange
Commission under the Securities Act of 1933.

        We have examined the form of Charter Amendment.  In addition, we have
examined, and have relied as to matters of fact upon, such other documents,
corporate records and other instruments, and have made such other and further
investigations, as we have deemed relevant and necessary as a basis for the
opinion hereinafter set forth.

        Based upon the foregoing, and subject to approval of the Charter
Amendment by the stockholders of the Company and the filing of the Charter
Amendment with the Secretary of State of the State of Delaware, we are of the
opinion that the Shares, when issued in accordance with the Merger Agreement,
will be validly issued, fully paid and nonassessable.

        We are members of the Bar of the State of New York and we do not express
any opinion herein concerning any law other than the federal law of the United
States and the Delaware General Corporation Law.

        We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to this firm under the caption
"Legal Opinions" in the Registration Statement.

                                       Very truly yours,

                                       /s/ Simpson Thacher & Bartlett

                                       SIMPSON THACHER & BARTLETT

                                      -2-

<PAGE>
 
                                                                     EXHIBIT 5.2
                                                       
     [LETTERHEAD OF BEARMAN TALESNICK & CLOWDUS PROFESSIONAL CORPORATION]

                                  June 9, 1995

Barrett Resources Corporation
1125 17th Street
Suite 2400
Denver, CO 80202

Gentlemen and Ladies:

     We have acted as counsel to Barrett Resources Corporation, a Delaware
corporation (the "Company"), in connection with the proposed issuance of shares
of common stock, par value $.01 per share ("Common Stock"), of the Company, in
connection with the Agreement And Plan Of Merger dated as of May 2, 1995 (the
"Merger Agreement") among the Company, Barrett Energy Inc. (formerly named
Vanilla Corporation) ("Barrett Energy") and Plains Petroleum Company ("Plains").
Following a special meeting of stockholders of the Company at which such
stockholders will be asked to approve, among other things, an amendment to the
Company's Certificate Of Incorporation to increase the Company's authorized
Common Stock to 35 million shares (the "Charter Amendment") and subject to
receipt of such approval and satisfaction or waiver of the other conditions to
the Merger set forth in the Merger Agreement, Barrett Energy will be merged with
and into Plains (the "Merger") and each outstanding share of common stock of
Plains will be converted into 1.3 shares of the Common Stock (in the aggregate,
the "Shares"), all as more fully described in the Registration Statement on Form
S-4 (the "Registration Statement") filed by the Company with the Securities And
Exchange Commission under the Securities Act of 1933.

     In connection with this opinion, we have examined the form of Charter
Amendment.  In addition, we have examined, and have relied as to matters of fact
upon, such other documents, corporate records and other instruments, and have
made such other and further investigations, as we have deemed relevant and
necessary as a basis for the opinion hereinafter set forth.  In our
examinations, we have assumed the genuineness of all signatures, the
authenticity of all documents submitted to us as originals, photostatic, or
conformed copies and the authenticity of the original of all such latter
documents.

     Based upon the foregoing, and subject to approval of the Charter Amendment
by the stockholders of the Company and the filing of the Charter Amendment with
the Secretary Of State of the State Of Delaware, we are of the opinion that the
Shares, when issued in accordance with the Merger Agreement, will be validly
issued, fully paid and nonassessable.

     We hereby consent (i) to be named in the Registration Statement, and in the
prospectus that constitutes a part thereof, as attorneys passing upon the
validity of the issuance of the Shares on behalf of the Company and (ii) to the
filing of this opinion as an Exhibit to the Company's Registration Statement.
<PAGE>
 
Barrett Resources Corporation
June 9, 1995
Page 2

     This opinion is to be used solely for the purpose of the registration of
the Shares and may not be used for any other purpose.

                                       Very truly yours,

                                       /s/ Bearman Talesnick & Clowdus
                                             Professional Corporation

                                       BEARMAN TALESNICK & CLOWDUS
                                        Professional Corporation

<PAGE>
 
                                                                     EXHIBIT 8.1

                  [Letterhead of Simpson Thacher & Bartlett]



 
                                       June 9, 1995



Barrett Resources Corporation
1125 Seventeenth Street
Suite 2400
Denver, Colorado  80202

Dear Sirs:

        We have acted as counsel to Barrett Resources Corporation (the
"Company") in connection with the preparation and filing of the Registration
Statement on Form S-4 with the Securities and Exchange Commission pursuant to
the Securities Act of 1933, as amended, in respect of the Agreement and Plan of
Merger, dated as of May 2, 1995, among the Company, Barrett Energy Inc.
(formerly named Vanilla Corporation) and Plains Petroleum Company.  In that
connection, we hereby confirm that the statements made in the Registration
Statement and related joint proxy statement under the caption "Certain Federal
Income Tax Consequences," insofar as they purport to constitute summaries of
matters of United States federal tax law and regulations or legal conclusions
with respect thereto, constitute accurate summaries of the matters described
therein in all material respects.
<PAGE>
 
Barrett Resources Corporation         -2-                           June 9, 1995


        We hereby consent to the filing of this letter as an Exhibit to the
Registration Statement.

        This opinion is rendered as of the date hereof based on the facts in
existence on the date hereof, and we undertake no, and hereby disclaim any,
obligation to advise you of any changes or any new developments, whether
material or not material, which may be brought to our attention at a later date.

        We do not express any opinion herein concerning any law other than the
federal law of the United States.

                                       Very truly yours,

                                       /s/ Simpson Thacher & Bartlett

                                       SIMPSON THACHER & BARTLETT

<PAGE>
 
                                                                     EXHIBIT 8.2

                        [Letterhead of Sidley & Austin]




                                 June 9, 1995


Plains Petroleum Company
12596 West Bayaud Avenue
Suite 400
Lakewood, Colorado 80228

Dear Sirs:

    We have acted as counsel to Plains Petroleum Company in connection with the 
preparation and filing of the Registration Statement on Form S-4 with the 
Securities and Exchange Commission pursuant to the Securities Act of 1933, as 
amended, in respect of the Agreement and Plan of Merger, dated as of May 2, 
1995, among Plains Petroleum Company, Barrett Energy Inc. and Barrett Resources 
Corporation.  In that connection, we hereby confirm that the statements made in
the Registration Statement and related joint proxy statement under the caption 
"Certain Federal Income Tax Consequences", insofar as they purport to constitute
summaries of matters of United States federal tax law and regulations or legal 
conclusions with respect thereto, constitute accurate summaries of the matters 
described therein in all material respects.

    We hereby consent to the filing of this letter as an Exhibit to the 
Registration Statement.

    This opinion is rendered as of the date hereof based on the facts in 
existence on the date hereof, and we undertake no, and hereby disclaim any, 
obligation to advise you of any changes or any new developments, whether
material or not material, which may be brought to our attention at a later date.


<PAGE>
 


Plains Petroleum Company
June 9, 1995
Page 2

    We do not express any opinion herein concerning any law other than the 
federal laws of the United States.

                                    Very truly yours,



                                /s/ SIDLEY & AUSTIN

<PAGE>
 
                                                                    EXHIBIT 23.1

                   CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
                   -----------------------------------------

        As independent public accountants, we hereby consent to the use of our 
reports (and to all references to our Firm) included in or made a part of this 
Registration Statement.

                                        /S/ ARTHUR ANDERSON LLP

Denver, Colorado
June 9, 1995

<PAGE>
 
                                                                    EXHIBIT 23.5


                         CONSENT OF RYDER SCOTT COMPANY

  We hereby consent to the references to Ryder Scott Company Petroleum Engineers
as experts in the field of petroleum engineering in the Registration Statement
(Form S-4) of Barrett Resources Corporation.

                       Very truly yours,

                   /s/ Ryder Scott Company Petroleum Engineers
                       ---------------------------------------
                       RYDER SCOTT COMPANY PETROLEUM ENGINEERS


Dated: June 9, 1995
       Denver, Colorado

<PAGE>
 
                                                                    EXHIBIT 23.6

June 8, 1995

Plains Petroleum Company
Suite 400
12596 West Bayaud Avenue
Lakewood, CO 80228

Gentlemen:

We hereby consent to the incorporation by reference in this registration
statement of the information from our "Estimate of Reserves and Future Revenue
to the Plains Petroleum Operating Company Interest in Certain Oil and Gas
Properties in the "Properties" section (Item 2(B)) appearing in your Annual
Report on Form 10-K and in Note Eight of the "Notes to Consolidated Financial
Statements" of your Annual Report to Shareholders (a) for the years ended
December 31, 1994, 1993, 1992, 1991, 1990, 1989, and 1988 into the previously
filed Registration Statements on Forms S-8/S-3 (Registration Nos. 33-3646 and
33-3648), each dated February 28, 1986, and on Form S-3 (Registration No. 33-
25095) dated November 8, 1988, (b) for the years ended December 331, 1994, 1993,
1992, 1991, and 1990 into the previously filed Registration Statement on Form S-
4 (Registration No. 33-34851) dated September 26, 1990, (d) for the years ended
December 31, 1994, 1993, 1992, and 1991 into the previously filed Registration
Statement on Form S-3 (Registration No. 33-43277) dated October 25, 1991, and
(e) for the years ended December 31, 1994, 1993, and 1992 into the previously
filed Registration Statement on Form S-8 (Registration No. 33-54636) dated
November 16, 1992, and on Form S-8 (Registration No. 33-35306) dated December
21, 1993.

                                           NETHERLAND, SEWELL & ASSOCIATES, INC.


                                           By: /s/ Frederic D. Sewell
                                               -------------------------
                                               Frederic D. Sewell
                                               President

<PAGE>

                                                                    EXHIBIT 99.1
 
                   FOR THE SPECIAL MEETING OF STOCKHOLDERS OF
P
                         BARRETT RESOURCES CORPORATION
R             PROXY SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS
 
O    The undersigned hereby appoints Paul M. Rady and J. Frank Keller, or either
   of them, as proxies with full power of substitution to vote all the shares of
X  the undersigned with all of the powers which the undersigned would possess if
   personally present at the Special Meeting Of Stockholders of Barrett
Y  Resources Corporation (the "Corporation"), to be held at 11:00 A.M., Denver
   time, on July 18, 1995, or any adjournments or postponements thereof, on the
   matters set forth on the reverse side hereof. Receipt of a copy of the Notice
   of Special Meeting and the related Joint Proxy Statement/Prospectus is hereby
   acknowledged.
 
                                     
                                     
        CONTINUED AND TO BE SIGNED ON THE REVERSE SIDE      SEE REVERSE
                                                                SIDE    
<PAGE>
 
 
 
[X]  PLEASE MARK 
     VOTES AS IN 
     THIS EXAMPLE.
 
 
UNLESS CONTRARY INSTRUCTIONS ARE GIVEN, THE SHARES REPRESENTED BY THIS PROXY
WILL BE VOTED IN FAVOR OF ITEMS 1 AND 2. THIS PROXY IS SOLICITED ON BEHALF OF
THE BOARD OF DIRECTORS OF BARRETT RESOURCES CORPORATION.

 
1. CHARTER AMENDMENT
   Proposal to authorize and approve an amendment to the Certificate of
   Incorporation to increase the authorized Common Stock from 17,000,000 shares
   to 35,000,000 shares.

                             FOR   AGAINST   ABSTAIN
                             [_]     [_]       [_]

2. STOCK ISSUANCE
   Proposal to authorize and approve the issuance of shares of Common Stock in
   connection with the Agreement and Plan of Merger dated as of May 2, 1995
   among Barrett Resources Corporation, Barrett Energy Inc., a wholly owned
   subsidiary of Barrett Resources Corporation ("Barrett Energy"), and Plains
   Petroleum Company ("Plains"), including the issuance of shares of Common
   Stock in the merger of Barrett Energy with and into Plains (the "Merger") and
   the reservation of shares of Common Stock for issuance upon exercise of stock
   options of Plains which, following the Merger, will constitute options to
   purchase Common Stock.

                             FOR   AGAINST   ABSTAIN
                             [_]     [_]       [_]

3. In their discretion, the proxies are authorized to vote upon such other
   business as may properly come before the meeting.

(Please sign exactly as shown on your stock certificate and on the envelope in
which this proxy was mailed. When signing as partner, corporate officer,
attorney, executor, administrator, trustee, guardian, etc., give full title as
such and sign your own name as well. If stock is held jointly, each joint owner
should sign.)

Signature: _____________________________________________    Date _______________

Signature: _____________________________________________    Date _______________

EVEN IF YOU PLAN TO ATTEND THE MEETING, PLEASE VOTE, DATE, SIGN AND RETURN THIS
PROXY IN THE ACCOMPANYING ENVELOPE.

<PAGE>
 
                                                                    EXHIBIT 99.2
P
                            PLAINS PETROLEUM COMPANY
R
          THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS
O
    The undersigned hereby appoints James A. Miller and William F. Wallace and
X   each of them proxies, will full power of substitution, to vote all shares of
    Common Stock of Plains Petroleum Company which the undersigned would be
Y   entitled to vote if personally present at the Special Meeting of
    Stockholders to be held on July 18, 1995 at 9:00 a.m. Denver Time, and at
    any adjournments or postponements thereof, upon the matters that may
    properly come before the meeting or any adjournments or postponements
    thereof. Said proxies are directed to vote as instructed on the matters set
P   forth below and otherwise in their discretion. Receipt of a copy of the
    Notice of said meeting and related Joint Proxy Statement/Prospectus is
R   hereby acknowledged.
 
O   1. Proposal to approve and adopt an Agreement and Plan of Merger, dated as
       of May 2, 1995, which appears as Annex I to the accompanying Joint Proxy
X      Statement/Prospectus, providing for the merger of Barrett Energy Inc., a
       wholly owned subsidiary of Barrett Resources Corporation, with and into
Y      Plains Petroleum Company.
 
                   [_] FOR    [_] AGAINST    [_] ABSTAIN
 
    2. In their discretion, the proxies are authorized to vote upon such other
       business as may properly come before the meeting.
 
    THIS PROXY WHEN PROPERLY EXECUTED WILL BE VOTED IN THE MANNER DIRECTED. IN
    THE ABSENCE OF DIRECTION, THIS PROXY WILL BE FOR PROPOSAL NO. 1.
 
                                                    ---------------------------
                                                            Signature
 
                                                    ---------------------------
                                                     Signature if held jointly
 
                                                    ---------------------------
                                                               Date
 
    IMPORTANT: PLEASE MARK AND DATE THE PROXY AND SIGN EXACTLY AS YOUR NAME OR
    NAMES APPEAR THEREON. If stock is held jointly, all joint owners must sign.
    Executors, administrators, trustees, guardians, custodians, corporate
    officers and others signing in a representative capacity should give their
    full titles.
 
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         
                                         

<PAGE>
 
                                                                    EXHIBIT 99.3

                      [LETTERHEAD OF RYDER SCOTT COMPANY]

                                 November 3, 1994



Barrett Resources Corporation
1125 Seventeenth Street, Suite 2100
Denver, Colorado 80202

Gentlemen:

       Pursuant to your request, we have reviewed your estimates of the net
proved reserves attributable to the interests of Barrett Resources Corporation
(referred to herein as the "Company") as of September 30, 1994.  This review
consisted of approximately 500 wells, and reserves attributed to certain behind
pipe zones and undeveloped locations which were evaluated by the reservoir
engineering staff of Barrett Resources Corporation.  The subject properties are
located in the States of Arkansas, Colorado, New Mexico, North Dakota, Oklahoma,
Texas and Wyoming.  Based on your reserve estimates, the proved net reserves as
of September 30, 1994 are presented below.
<TABLE>
<CAPTION>
                                       Reviewed
                                   Proved Net Reserves
                       Prepared by Barrett Resources Corporation
                                 As of September 30, 1994
                       -----------------------------------------
                            Liquid, Barrels         Gas, MMCF
                       -------------------------  --------------
<S>                    <C>                        <C>
 
       Developed               333,364                80,012
                                            
       Undeveloped             151,016                69,194
                               -------               -------
                                            
       Total Proved            484,380               149,206
</TABLE>

       In general, it is our opinion that the methods and techniques used in
preparing your report are in accordance with generally accepted procedures for
the determination of reserves. Further, in our judgement, there was no evidence
of bias in the application of the methods and techniques for estimating proved
reserves, and that the total proved net reserves estimated would be within 10
percent of those estimated by Ryder Scott Company.  However, on a well by well
comparison, differences of greater than 10 percent may exist.

       Total proved developed reserves in the Grand Valley-Rulison Field Area,
Garfield County, Colorado and the North Waltman Area in Natrona County, Wyoming
have established significant proved undeveloped reserves.  Because of the direct
relationship between quantities of proved undeveloped reserves and development
plans, we have included in the proved undeveloped category only reserves
assigned to undeveloped locations that we have been assured will definitely be
drilled.  As with all reserves estimates, future development and performance
data, as well as changes in the market prices of oil, condensate and gas may
necessitate significant revisions in the estimates of reserves prepared at a
future date for these wells and undeveloped locations.

       The proved reserves presented in your report comply with the Securities
and Exchange Commission's Regulation S-X Part 210.4-10(a) as clarified by the
Commission's Staff Accounting Bulletin No. 40, and are based on the following
definitions and criteria:

       Proved reserves of crude oil, condensate, natural gas, or natural gas
       ---------------                                                      
liquids are estimated quantities that geological and engineering data
demonstrate with reasonable certainty to be recoverable in the future from known
reservoirs under existing conditions.  Reservoirs are considered proved if
economic producibility is supported by actual production or formation tests.  In
certain instances, proved reserves may be assigned on the basis of
<PAGE>
 
Barrett Resources Corporation
November 3, 1994
Page 2

a combination of core analysis and electrical and other type logs which indicate
the reservoirs are analogous to reservoirs in the same field which are producing
or have demonstrated the ability to produce on a formation test. The area of a
reservoir considered proved includes (1) that portion delineated by drilling and
defined by fluid contacts, if any, and (2) the adjoining portions not yet
drilled that can be reasonably judged as economically productive on the basis of
available geological and engineering data. In the absence of data on fluid
contacts, the lowest known structural occurrence of hydrocarbons controls the
lower proved limit of the reservoir. Proved reserves are estimates of
hydrocarbons to be recovered from a given date forward. They may be revised as
hydrocarbons are produced and additional data become available. Proved natural
gas reserves consist of non-associated, associated and dissolved gas. An
appropriate reduction in gas reserves has been made for the expected removal of
natural gas liquids, for lease and plant fuel, and for the exclusion of non-
hydrocarbon gases if they occur in significant quantities and are removed prior
to sale. Reserves that can be produced economically through the application of
established improved recovery techniques are included in the proved
classification when these qualifications are met: (1) successful testing by a
pilot project or the operation of an installed program in that reservoir or one
in the immediate area with similar rock and fluid properties provides support
for the engineering analysis on which the project or program was based, and (2)
it is reasonably certain the project will proceed. Reserves to be recovered by
improved recovery techniques that have yet to be established through repeated
economically successful applications are included in the proved category only
after successful testing by a pilot project or after the operation of an
installed program in the reservoir provides support for the engineering analysis
on which the project or program was based. Improved recovery includes all
methods for supplementing natural reservoir forces and energy, or otherwise
increasing ultimate recovery from a reservoir, including (1) pressure
maintenance, (2) cycling, and (3) secondary recovery in its original sense.
Improved recovery also includes the enhanced recovery methods of thermal,
chemical flooding, and the use of miscible and immiscible displacement fluids.
Estimates of proved reserves do not include crude oil, condensate, natural gas,
or natural gas liquids being held in underground storage. Depending on the
status of development, these proved reserves are further subdivided into:

       (i) "developed reserves" which are those proved reserves reasonably
       expected to be recovered through existing wells with existing equipment
       and operating methods, including (a) "developed producing reserves" which
       are those proved developed reserves reasonably expected to be produced
       from existing completion intervals now open for production in existing
       wells, and (b) "developed non-producing reserves" which are those proved
       developed reserves which exist behind the casing of existing wells which
       are reasonably expected to be produced through these wells in the
       predictable future where the cost of making such hydrocarbons available
       for production should be relatively small compared to the cost of a new
       well; and

       (ii) "undeveloped reserves" which are those proved reserves reasonably
       expected to be recovered from new wells on undrilled acreage, from
       existing wells where a relatively large expenditure is required and from
       acreage for which an application of fluid injection or other improved
       recovery technique is contemplated where the technique has been proved
       effective by actual tests in the area in the same reservoir or one with
       similar rock and fluid properties.  Reserves from undrilled acreage are
       limited to those drilling units offsetting productive units that are
       reasonably certain of production when drilled.  Proved reserves for other
       undrilled units are included only where it can be demonstrated with
<PAGE>
 
Barrett Resources Corporation
November 3, 1994
Page 3

       reasonable certainty that there is continuity of production from the
       existing productive formation.

       The Company has interests in certain tracts which have substantial
additional hydrocarbon quantities which cannot be classified as proved and
consequently are not included herein.  The Company has active exploratory and
development drilling programs which in all likelihood will result in the
reclassification of significant additional quantities to the proved category.

       Our reserve estimates are based upon a detailed study of the properties
in which the Company has interests; however, we have not made any field
examination of the properties.  The Company informed us that it has furnished us
all of the accounts, records, geological and engineering data and reports and
other data as were required for our investigation.  The ownership interests,
prices and other factual data furnished to us in connection with our
investigation were accepted as represented.

       Neither Ryder Scott Company nor any of its employees has any interest in
the subject properties and neither the employment to make this study nor the
compensation is contingent on our estimates of reserves and future cash inflows
for the subject properties.

                                 Very truly yours,

                                 RYDER SCOTT COMPANY
                                 PETROLEUM ENGINEERS

                                 /s/ GARY KRIEGER

                                 Gary Krieger, P. E.
                                 Petroleum Engineer

GK:clb

APPROVED:

/s/ LARRY T. NELMS

Larry T. Nelms, P. E.
Group Vice President

<PAGE>
 
                                                                    EXHIBIT 99.4

                      [LETTERHEAD OF RYDER SCOTT COMPANY]

                                  June 5, 1995



Barrett Resources Corporation
1125 Seventeenth Street, Suite 2400
Denver, Colorado 80202

Gentlemen:

          Pursuant to your request, we have reviewed your estimates of the net
proved reserves attributable to the interests of Barrett Resources Corporation
(referred to herein as the "Company") as of March 31, 1995.  For this review the
reserves as of September 30, 1994 were mechanically adjusted for production to
March 31, 1995 and revisions were made for any interest changes and reserve
clanssifications to the existing properties.  Ryder Scott Company has reviewed
the reserves associated with the Rulison Field Area in Garfield County, Colorado
and the North Waltman Area in Natrona County, Wyoming because of the significant
changes in the reserves associated with these two fields since September 30,
1994.  Ryder Scott has not reviewed any additional production data after the
September 30, 1994 review for any wells that were not included in the Rulison
Field or the North Waltman Area.  Barrett Resources Corporation has represented
to Ryder Scott Company that the net reserves associated with their Oklahoma
properties may have changed significantly on a well by well basis, but the total
net reserves in Oklahoma are approximately the same after adjusting for
production at March 31, 1995.  Ryder Scott Company has not reviewed any of these
revisions.  The September 30, 1994 review consisted of approximately 500 wells,
and reserves attributed to certain behind pipe zones and undeveloped locations
which were evaluated by the reservoir engineering staff of Barrett Resources
Corporation.  The subject properties are located in the States of Arkansas,
Colorado, New Mexico, North Dakota, Oklahoma, Texas and Wyoming.  Based on your
reserve estimates, the proved net reserves as of March 31, 1995 are presented
below.
<TABLE>
<CAPTION>
 
                                Reviewed
                          Proved Net Reserves
                Prepared by Barrett Reources Corporation
                          As of March 31, 1995
                ----------------------------------------
 
                  Liquid, Barrels            Gas, MMCF
                  ---------------            ---------
<S>               <C>                        <C>
Developed              414,876                 94,387
Undeveloped            485,973                131,529
                       -------                -------
Total Proved           900,849                225,916
 
</TABLE>
<PAGE>
 
Barrett Resources Corportion
June 5, 1995
Page 2

          In general, it is our opinion that the methods and techniques used in
preparing your report are in accordance with generally accepted procedures for
the determination of reserves. Further, in our judgment, there was no evidence
of bias in the application of the methods and techniques for estimating proved
reserves, and that the total proved net reserves estimated would be within 10
percent of those estimated by Ryder Scott Company based on our September 30,
1994 review except for the Rulison Field Area and the North Waltman Area which
we reviewed at March 31, 1995.  However, on a well by well comparison,
differences of greater than 10 percent may exist.

          Total proved developed reserves in the Grand Valley-Rulison Field
Area, Garfield County, Colorado and the North Waltman Area in Natrona County,
Wyoming have established significant proved undeveloped reserves.  Because of
the direct relationship between quantities of proved undeveloped reserves and
development plans, we have included in the proved undeveloped category only
reserves assigned to undeveloped locations that we have been assured will
definitely be drilled.  As with all reserves estimates, future development and
performance data, as well as changes in the market prices of oil, condensate and
gas may necessitate significant revisions in the estimates of reserves prepared
at a future date for these wells and undeveloped locations.

          The proved reserves presented in your report comply with the
Securities and Exchange Commission's Regulation S-X Part 210.4-10(a) as
clarified by the Commission's Staff Accounting Bulletin No. 40, and are based on
the following definitions and criteria:

               Proved reserves of crude oil, condensate, natural gas, or natural
               ---------------                                                  
          gas liquids are estimated quantities that geological and engineering
          data demonstrate with reasonable certainty to be recoverable in the
          future from known reservoirs under existing conditions.  Reservoirs
          are considered proved if economic producibility is supported by actual
          production or formation tests.  In certain instances, proved reserves
          may be assigned on the basis of a combination of core analysis and
          electrical and other type logs which indicate the reservoirs are
          analogous to reservoirs in the same field which are producing or have
          demonstrated the ability to produce on a formation test.  The area of
          a reservoir considered proved includes (1) that portion delineated by
          drilling and defined by fluid contacts, if any, and (2) the adjoining
          portions not yet drilled that can be reasonably judged as economically
          productive on the basis of available geological and engineering data.
          In the absence of data of fluid contacts, the lowest known structural
          occurrence by hydrocarbons controls the lower proved limit of the
          reservoir.  Proved reserves are estimates of hydrocarbons to be
          recovered from a given date forward.  They may be revised as
          hydrocarbons are produced and additional data become available.
          Proved natural gas reserves consist of non-associated, associated and
          dissolved gas.  An appropriate reduction in gas reserves has been made
          for the expected removal of natural gas liquids, for lease and plant
          fuel, and for the exclusion of non-hydrocarbon gases if they occur in
          significant quantities and are removed prior to sale.  Reserves that
          can be produced economically through the application of established
          improved recovery techniques are included in the proved classification
          when these qualifications are met: (1) successful testing by a pilot
          project or the operation of an installed program in that reservoir or
          one in the immediate area with similar rock and fluid properties
          provides support for the engineering analysis on which the project or
          program was based, and (2) it is reasonably certain the project will
          proceed.  Reserves to be recovered by improved recovery techniques
          that have yet to be established through repeated economically
          successful applications are included in the proved category only after
          successful testing by a pilot project or after the operation of an
          installed program in the reservoir provides support for the
          engineering analysis on which the project or program was based.
          Improved recovery includes all methods for supplementing natural
<PAGE>
 
Barrett Resources Corporation
June 5, 1995
Page 3

          reservoir forces and energy, or otherwise increasing ultimate recovery
          from a reservoir, including (1) pressure maintenance, (2) cycling, and
          (3) secondary recovery in its original sense.  Improved recovery also
          includes the enhanced recovery methods of thermal, chemical flooding,
          and the use of miscible and immiscible displacement fluids.  Estimates
          of proved reserves do not include crude oil, condensate, natural gas,
          or natural gas liquids being held in underground storage.  Depending
          on the status of development, these proved reserves are further
          subdivided into:

               (i) "developed reserves" which are those proved reserves
               reasonably expected to be recovered through existing wells with
               existing equipment and operating methods, including (a)
               "developed producing reserves" which are those proved developed
               reserves reasonably expected to be produced from existing
               completion intervals now open for production in existing wells,
               and (b) "developed non-producing reserves" which are those proved
               developed reserves which exist behind the casing of existing
               wells which are reasonably expected to be produced through these
               wells in the predictable future where the cost of making such
               hydrocarbons available for production should be relatively small
               compared to the cost of a new well; and

                 (ii) "undeveloped reserves" which are those proved reserves
               reasonably expected to be recovered from new wells on undrilled
               acreage, from existing wells where a relatively large expenditure
               is required and from acreage for which an application of fluid
               injection or other improved recovery technique is contemplated
               where the technique has been proved effective by actual tests in
               the area in the same reservoir or one with similar rock and fluid
               properties.  Reserves from undrilled acreage are limited to those
               drilling units offsetting productive units that are reasonably
               certain of production when drilled.  Proved reserves for other
               undrilled units are included only where it can be demonstrated
               with reasonable certainty that there is continuity of production
               from the existing productive formation.

          The Company has interests in certain tracts which have substantial
additional hydrocarbon quantities which cannot be classified as proved and
consequently are not included herein.  The Company has active exploratory and
development drilling programs which in all likelihood will result in the
reclassification of significant additional quantities to the proved category.

          Our reserve estimates are based upon a detailed study of the
properties in which the Company has interests; however, we have not made any
field examination of the properties.  The Company informed us that it has
furnished us all of the accounts, records, geological and engineering data and
reports and other data as were required for our investigation.  The ownership
interests, prices and other factual data furnished to us in connection with our
investigation were accepted as represented.
<PAGE>
 
Barrett Resources Corporation
June 5, 1995
Page 4

          Neither Ryder Scott Company nor any of its employees has any interest
in the subject properties and neither the employment to make this study nor the
compensation is contingent on our estimates of reserves and future cash inflows
for the subject properties.

                                    Very truly yours,

                                    RYDER SCOTT COMPANY
                                    PETROLEUM ENGINEERS

                                    /s/ GARY KRIEGER

                                    Gary Krieger, P.E.
                                    Petroleum Engineer

GK:clb

APPROVED:

/s/ LARRY T. NELMS

Larry T. Nelms, P.E.
Senior Vice President


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