<ARTICLE> 5 <MULTIPLIER> 1,000 <CURRENCY> U.S. DOLLARS <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-START> JAN-01-1997 <PERIOD-END> MAR-31-1997 <EXCHANGE-RATE> 1 <CASH> 27,129 <SECURITIES> 0 <RECEIVABLES> 19,746 <ALLOWANCES> 0 <INVENTORY> 0 <CURRENT-ASSETS> 49,001 <PP&E> 203,998 <DEPRECIATION> 118,806 <TOTAL-ASSETS> 180,514 <CURRENT-LIABILITIES> 23,018 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 109 <OTHER-SE> 137,610 <TOTAL-LIABILITY-AND-EQUITY> 180,514 <SALES> 21,030 <TOTAL-REVENUES> 30,861 <CGS> 3,978 <TOTAL-COSTS> 3,978 <OTHER-EXPENSES> (35) <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 582 <INCOME-PRETAX> 18,044 <INCOME-TAX> 6,449 <INCOME-CONTINUING> 11,595 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 11,595 <EPS-PRIMARY> 1 <EPS-DILUTED> 1