<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 12-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-END> DEC-31-1998 <CASH> 74,618 <SECURITIES> 12,200 <RECEIVABLES> 136,080 <ALLOWANCES> 6,272 <INVENTORY> 19,772 <CURRENT-ASSETS> 254,794 <PP&E> 1,787,424 <DEPRECIATION> 837,704 <TOTAL-ASSETS> 1,605,640 <CURRENT-LIABILITIES> 187,681 <BONDS> 255,766 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 36,098 <OTHER-SE> 658,544 <TOTAL-LIABILITY-AND-EQUITY> 1,605,640 <SALES> 1,292,664 <TOTAL-REVENUES> 1,311,620 <CGS> 1,083,836 <TOTAL-COSTS> 1,083,836 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 24,799 <INCOME-PRETAX> 55,295 <INCOME-TAX> 24,352 <INCOME-CONTINUING> 30,943 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> (5,801) <NET-INCOME> 25,142 <EPS-PRIMARY> 0.56 <EPS-DILUTED> 0.56