<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> SEP-30-1997 <CASH> 1,795 <SECURITIES> 0 <RECEIVABLES> 37,510 <ALLOWANCES> (629) <INVENTORY> 9,104 <CURRENT-ASSETS> 50,126 <PP&E> 1,058,046 <DEPRECIATION> (547,877) <TOTAL-ASSETS> 561,213 <CURRENT-LIABILITIES> 79,965 <BONDS> 233,000 <PREFERRED-MANDATORY> 0 <PREFERRED> 91,321 <COMMON> 156,915 <OTHER-SE> (73,859) <TOTAL-LIABILITY-AND-EQUITY> 561,213 <SALES> 127,211 <TOTAL-REVENUES> 132,972 <CGS> 89,763 <TOTAL-COSTS> 89,763 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 13,533 <INCOME-PRETAX> 30,025 <INCOME-TAX> 11,914 <INCOME-CONTINUING> 13,936 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 13,936 <EPS-PRIMARY> 0.61 <EPS-DILUTED> 0