<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                        
<PERIOD-TYPE>                              6-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               JUN-30-1998
<CASH>                                           1,976
<SECURITIES>                                         0
<RECEIVABLES>                                   24,187
<ALLOWANCES>                                         0
<INVENTORY>                                     19,358
<CURRENT-ASSETS>                                49,562
<PP&E>                                         995,055
<DEPRECIATION>                                (458,395)
<TOTAL-ASSETS>                                 611,683
<CURRENT-LIABILITIES>                           47,951
<BONDS>                                        259,071
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0    
<COMMON>                                         2,774
<OTHER-SE>                                     183,185
<TOTAL-LIABILITY-AND-EQUITY>                   611,683
<SALES>                                        135,343
<TOTAL-REVENUES>                               139,290
<CGS>                                                0
<TOTAL-COSTS>                                  183,202
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               8,188
<INCOME-PRETAX>                                (54,076)
<INCOME-TAX>                                   (21,090)
<INCOME-CONTINUING>                            (32,986)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (32,986)
<EPS-PRIMARY>                                    (1.33)
<EPS-DILUTED>                                        0