<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET AT JUNE 30, 2000 AND THE RELATED STATEMENT OF
CONSOLIDATED OPERATIONS FOR THE 6 MONTHS ENDED JUNE 30, 2000 AND IS QUALIFIED IN
ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<CASH> 263,185
<SECURITIES> 5,820
<RECEIVABLES> 33,142
<ALLOWANCES> 0
<INVENTORY> 53,318
<CURRENT-ASSETS> 379,863
<PP&E> 2,668,371
<DEPRECIATION> (1,617,908)
<TOTAL-ASSETS> 1,534,027
<CURRENT-LIABILITIES> 120,440
<BONDS> 279,638
0
0
<COMMON> 253,925
<OTHER-SE> 437,463
<TOTAL-LIABILITY-AND-EQUITY> 1,534,027
<SALES> 333,602
<TOTAL-REVENUES> 325,904
<CGS> 288,136<F1>
<TOTAL-COSTS> 310,476<F2>
<OTHER-EXPENSES> 20,649<F3>
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 9,886
<INCOME-PRETAX> (15,107)
<INCOME-TAX> (3,059)
<INCOME-CONTINUING> (17,334)
<DISCONTINUED> (15,346)
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (32,680)
<EPS-BASIC> (0.13)
<EPS-DILUTED> (0.13)
<FN>
<F1>Includes production costs and Depreciation, depletion and amortization from the
Statement of Consolidated Operations.
<F2>Includes production costs and Depreciation, depletion and amortization and
Administrative and general expense from the Statement of Consolidated
Operations.
<F3>Includes Exploration expense, Write-downs and other unusual charges, Business
combination and integration costs, and Other expense from the Statement of
Consolidated Operations.
</FN>
</TABLE>
