<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY INFORMATION EXTRACTED FROM CONDENSED CONSOLIDATED
BALANCE SHEETS AND STATEMENTS OF OPERATIONS AS OF MARCH 31, 1997, JUNE 30, 1997,
AND SEPTEMBER 30, 1997, AND FOR THE THREE, SIX AND NINE MONTH PERIODS,
RESPECTIVELY, THEN ENDED, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                         117,348                  96,750                 118,544
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                   59,843                  71,610                  73,977
<ALLOWANCES>                                     2,862                   1,666                   2,123
<INVENTORY>                                     41,325                  46,099                  41,958
<CURRENT-ASSETS>                               232,700                 230,144                 398,316
<PP&E>                                       1,145,345               1,154,554               1,176,625
<DEPRECIATION>                                 333,329                 345,515                 357,913
<TOTAL-ASSETS>                               1,057,738               1,051,856               1,230,345
<CURRENT-LIABILITIES>                          134,691                 131,723                 301,938
<BONDS>                                        344,770                 344,142                 344,142
<PREFERRED-MANDATORY>                              284                     284                     284
<PREFERRED>                                          0                       0                       0
<COMMON>                                             0                       0                       0
<OTHER-SE>                                     143,575                 150,355                 166,147
<TOTAL-LIABILITY-AND-EQUITY>                 1,057,738               1,051,856               1,230,345
<SALES>                                        152,152                 293,843                 445,334
<TOTAL-REVENUES>                               164,652                 348,055                 586,260
<CGS>                                          128,231                 240,533                 360,869
<TOTAL-COSTS>                                  139,399                 250,692                 372,331
<OTHER-EXPENSES>                                 5,272                  54,879                 145,872
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                               4,111                   8,637                  12,712
<INCOME-PRETAX>                                 15,870                  33,847                  55,345
<INCOME-TAX>                                     2,856                   6,090                   9,959
<INCOME-CONTINUING>                             13,014                  27,757                  45,386
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                    13,014                  27,757                  45,386
<EPS-PRIMARY>                                      .46                     .98                    1.60
<EPS-DILUTED>                                      .45                     .96                    1.58


</TABLE>