<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 DECEMBER 31,
1999 AND CONSOLIDATED STATEMENT OF INCOME FOR THE YEAR ENDED DECEMBER 31, 1999,
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<CASH> 68,228
<SECURITIES> 0
<RECEIVABLES> 521,948
<ALLOWANCES> 0
<INVENTORY> 78,349
<CURRENT-ASSETS> 772,140
<PP&E> 1,190,167
<DEPRECIATION> 402,514
<TOTAL-ASSETS> 1,689,560
<CURRENT-LIABILITIES> 656,273
<BONDS> 0
138,813
23,300
<COMMON> 1,792
<OTHER-SE> 15,527
<TOTAL-LIABILITY-AND-EQUITY> 1,689,560
<SALES> 4,742,690
<TOTAL-REVENUES> 4,770,171
<CGS> 4,740,862
<TOTAL-COSTS> 4,809,262
<OTHER-EXPENSES> 0
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 46,378
<INCOME-PRETAX> (45,266)
<INCOME-TAX> (20,479)
<INCOME-CONTINUING> (24,787)
<DISCONTINUED> 0
<EXTRAORDINARY> (544)
<CHANGES> 0
<NET-INCOME> (25,331)
<EPS-BASIC> (2.05)
<EPS-DILUTED> (2.05)
</TABLE>