<ARTICLE> 5
<MULTIPLIER>     1,000
       
                                                  
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996
<PERIOD-START>                             JUL-01-1997             JAN-01-1997
<PERIOD-END>                               SEP-30-1997             SEP-30-1997
<CASH>                                           6,704                   6,704
<SECURITIES>                                         0                       0
<RECEIVABLES>                                   42,520                  42,520
<ALLOWANCES>                                         0                       0
<INVENTORY>                                      2,527                   2,527
<CURRENT-ASSETS>                                55,120                  55,120
<PP&E>                                       1,300,665               1,300,665
<DEPRECIATION>                                 460,829                 460,829
<TOTAL-ASSETS>                                 911,262                 911,262
<CURRENT-LIABILITIES>                           54,092                  54,092
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                          115,000                 115,000
<PREFERRED>                                          0                       0
<COMMON>                                           203                     203
<OTHER-SE>                                     390,539                 390,539
<TOTAL-LIABILITY-AND-EQUITY>                   911,262                 911,262
<SALES>                                         83,771                 266,817
<TOTAL-REVENUES>                                83,717                 270,744
<CGS>                                           56,118                 172,872
<TOTAL-COSTS>                                   56,118                 172,872
<OTHER-EXPENSES>                                10,616                  28,788
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                               6,585                  20,593
<INCOME-PRETAX>                                 10,398                  48,491
<INCOME-TAX>                                     4,186                  19,518
<INCOME-CONTINUING>                              6,215                  28,981
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                   3,024
<CHANGES>                                            0                       0
<NET-INCOME>                                     6,215                  25,957
<EPS-PRIMARY>                                      .31                    1.27
<EPS-DILUTED>                                        0                       0