<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> MAR-31-1997 <CASH> 22,551 <SECURITIES> 32,573 <RECEIVABLES> 23,823 <ALLOWANCES> 0 <INVENTORY> 3,584 <CURRENT-ASSETS> 82,531 <PP&E> 1,516,364 <DEPRECIATION> 583,954 <TOTAL-ASSETS> 1,027,945 <CURRENT-LIABILITIES> 120,505 <BONDS> 335,000 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 0 <OTHER-SE> 409,353 <TOTAL-LIABILITY-AND-EQUITY> 1,027,945 <SALES> 0 <TOTAL-REVENUES> 46,646 <CGS> 0 <TOTAL-COSTS> 22,828 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 7,861 <INCOME-PRETAX> 13,471 <INCOME-TAX> 0 <INCOME-CONTINUING> 13,471 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 13,471 <EPS-PRIMARY> 0.50 <EPS-DILUTED> 0.50