<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S SEC FORM 10-Q FOR THE PERIOD ENDING JUNE 30, 1996 AND IS QUALIFIED IN
ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-END>                               JUN-30-1996
<CASH>                                          14,261
<SECURITIES>                                         0
<RECEIVABLES>                                   88,301
<ALLOWANCES>                                        76
<INVENTORY>                                     34,812
<CURRENT-ASSETS>                               181,522
<PP&E>                                       2,937,996
<DEPRECIATION>                               1,403,057
<TOTAL-ASSETS>                               1,839,365
<CURRENT-LIABILITIES>                          200,016
<BONDS>                                        644,071
<COMMON>                                         4,391
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<OTHER-SE>                                     485,094
<TOTAL-LIABILITY-AND-EQUITY>                 1,839,365
<SALES>                                        481,370
<TOTAL-REVENUES>                               497,306
<CGS>                                          161,322
<TOTAL-COSTS>                                  277,305
<OTHER-EXPENSES>                                24,465
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              14,510
<INCOME-PRETAX>                                181,026
<INCOME-TAX>                                   102,628
<INCOME-CONTINUING>                             78,398
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    78,398
<EPS-PRIMARY>                                      .90
<EPS-DILUTED>                                        0