<TABLE> <S> <C>

<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   YEAR                   YEAR                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1997             DEC-31-1998
<PERIOD-END>                               DEC-31-1996             DEC-31-1997             DEC-31-1998
<CASH>                                           13417                   42065                   19154
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                    63942                   96828                   83858
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                       4310                    4012                    2750
<CURRENT-ASSETS>                                233643                  213257                  110648
<PP&E>                                         1488336                 2320735                 2610511
<DEPRECIATION>                                  568789                 1325452                 1509583
<TOTAL-ASSETS>                                 1183290                 1248986                 1226356
<CURRENT-LIABILITIES>                           146807                  136314                   80656
<BONDS>                                          83000                  305337                  405271
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                          4288                    4829                    4842
<OTHER-SE>                                      674484                  591717                  518121
<TOTAL-LIABILITY-AND-EQUITY>                   1183290                 1248986                 1226356
<SALES>                                         256765                  452104                  369660
<TOTAL-REVENUES>                                291335                  499659                  387508
<CGS>                                                0                       0                       0
<TOTAL-COSTS>                                        0                       0                       0
<OTHER-EXPENSES>                                 69614                  120124                  127400
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                               12662                   18788                   22632
<INCOME-PRETAX>                                 118689                (473833)                 (75792)
<INCOME-TAX>                                     51086                (173842)                 (15507)
<INCOME-CONTINUING>                              67603                (299991)                 (60285)
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                     67603                (299991)                 (60285)
<EPS-PRIMARY>                                     2.06                  (6.38)                  (1.25)
<EPS-DILUTED>                                     1.99                  (6.38)                  (1.25)
        

</TABLE>