<ARTICLE> 5 <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> MAR-31-1997 <CASH> 4,230 <SECURITIES> 0 <RECEIVABLES> 12,947 <ALLOWANCES> 0 <INVENTORY> 7,656 <CURRENT-ASSETS> 26,766 <PP&E> 1,080,240 <DEPRECIATION> 732,660 <TOTAL-ASSETS> 376,997 <CURRENT-LIABILITIES> 35,434 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 0 <OTHER-SE> 0 <TOTAL-LIABILITY-AND-EQUITY> 376,997 <SALES> 66,283 <TOTAL-REVENUES> 66,283 <CGS> 17,496 <TOTAL-COSTS> 17,744 <OTHER-EXPENSES> 310 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 21 <INCOME-PRETAX> 48,345 <INCOME-TAX> 30,919 <INCOME-CONTINUING> 17,426 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 17,426 <EPS-PRIMARY> 0 <EPS-DILUTED> 0