<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 12-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> DEC-31-1997 <CASH> (1,077) <SECURITIES> 22,700 <RECEIVABLES> 194,170 <ALLOWANCES> 18,005 <INVENTORY> 69,209 <CURRENT-ASSETS> 288,941 <PP&E> 1,975,023 <DEPRECIATION> 938,508 <TOTAL-ASSETS> 1,704,798 <CURRENT-LIABILITIES> 174,135 <BONDS> 290,885 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 36,769 <OTHER-SE> 682,819 <TOTAL-LIABILITY-AND-EQUITY> 1,704,798 <SALES> 1,233,344 <TOTAL-REVENUES> 1,275,445 <CGS> 1,011,718 <TOTAL-COSTS> 1,011,718 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 28,936 <INCOME-PRETAX> 127,212 <INCOME-TAX> 45,825 <INCOME-CONTINUING> 81,387 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 81,387 <EPS-PRIMARY> 1.80 <EPS-DILUTED> 1.80