<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM PLAINS
RESOURCES, INC. AND SUBSIDIARIES CONSOLIDATED BALANCE SHEET AS OF MARCH 31, 2000
AND CONSOLIDATED STATEMENT OF INCOME FOR THE THREE MONTHS ENDED MARCH 31, 2000,
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<S> <C>
<PERIOD-TYPE> 3-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> MAR-31-2000
<CASH> 17,626
<SECURITIES> 0
<RECEIVABLES> 525,612
<ALLOWANCES> 0
<INVENTORY> 59,649
<CURRENT-ASSETS> 602,887
<PP&E> 1,206,445
<DEPRECIATION> 410,591
<TOTAL-ASSETS> 1,504,065
<CURRENT-LIABILITIES> 542,115
<BONDS> 0
138,813
23,300
<COMMON> 1,795
<OTHER-SE> 32,163
<TOTAL-LIABILITY-AND-EQUITY> 1,504,065
<SALES> 986,939
<TOTAL-REVENUES> 1,039,941
<CGS> 932,980
<TOTAL-COSTS> 959,273
<OTHER-EXPENSES> 0
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 15,874
<INCOME-PRETAX> 35,210
<INCOME-TAX> 13,732
<INCOME-CONTINUING> 21,478
<DISCONTINUED> 0
<EXTRAORDINARY> (1,365)
<CHANGES> 0
<NET-INCOME> 20,113
<EPS-BASIC> 0.91
<EPS-DILUTED> 0.68
</TABLE>