<ARTICLE>                     5
<LEGEND>
This  schedule  contains  summary  financial   information  extracted  from  the
Consolidated  Balance  Sheet  at June  30,  1998 and the  related  Statement  of
Consolidated  Operations for the six months ended June 30, 1998 and is qualified
in its entirety by reference to such financial statements.
</LEGEND>
<MULTIPLIER>                                   1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                                DEC-31-1998      
<PERIOD-END>                                     JUN-30-1998
<CASH>                                               134,219
<SECURITIES>                                         149,699
<RECEIVABLES>                                         48,711
<ALLOWANCES>                                               0
<INVENTORY>                                           83,431
<CURRENT-ASSETS>                                     450,194
<PP&E>                                             2,204,344
<DEPRECIATION>                                     1,271,610
<TOTAL-ASSETS>                                     1,505,461
<CURRENT-LIABILITIES>                                142,436
<BONDS>                                              356,069
<PREFERRED-MANDATORY>                                      0
<PREFERRED>                                                0
<COMMON>                                             211,162
<OTHER-SE>                                           393,586
<TOTAL-LIABILITY-AND-EQUITY>                       1,505,461
<SALES>                                              416,824
<TOTAL-REVENUES>                                     411,502
<CGS>                                                351,798 <F1>
<TOTAL-COSTS>                                        375,635 <F2>
<OTHER-EXPENSES>                                      55,098 <F3>
<LOSS-PROVISION>                                           0
<INTEREST-EXPENSE>                                    10,328
<INCOME-PRETAX>                                      (29,559)  
<INCOME-TAX>                                           2,342 
<INCOME-CONTINUING>                                  (37,517)
<DISCONTINUED>                                             0
<EXTRAORDINARY>                                            0
<CHANGES>                                                  0
<NET-INCOME>                                         (37,517)
<EPS-PRIMARY>                                          (0.18)
<EPS-DILUTED>                                          (0.18)

<FN>
<F1> Includes  Production  costs and  Depreciation,  depletion and  amortization
     from the Statement of Consolidated Operations.
<F2> Includes  Production  costs,  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>