<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S SEC FORM 10-Q FOR THE PERIOD ENDING MARCH 31, 1996 AND IS QUALIFIED IN
ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-END>                               MAR-31-1996
<CASH>                                          11,860
<SECURITIES>                                         0
<RECEIVABLES>                                   73,042
<ALLOWANCES>                                        75
<INVENTORY>                                     42,382
<CURRENT-ASSETS>                               152,154
<PP&E>                                       2,865,564
<DEPRECIATION>                               1,344,358
<TOTAL-ASSETS>                               1,796,383
<CURRENT-LIABILITIES>                          204,184
<BONDS>                                        640,796
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         4,391
<OTHER-SE>                                     459,546
<TOTAL-LIABILITY-AND-EQUITY>                 1,796,383
<SALES>                                        258,178
<TOTAL-REVENUES>                               267,556
<CGS>                                           80,064
<TOTAL-COSTS>                                  140,670
<OTHER-EXPENSES>                                14,207
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               7,848
<INCOME-PRETAX>                                104,831
<INCOME-TAX>                                    57,270
<INCOME-CONTINUING>                             47,561
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    47,561
<EPS-PRIMARY>                                      .54
<EPS-DILUTED>                                        0