<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONDENSED FINANCIAL STATEMENTS FOR THE NINE MONTH PERIOD ENDED SEPTEMBER 30,
1997, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               SEP-30-1997
<CASH>                                           1,317
<SECURITIES>                                         0
<RECEIVABLES>                                   22,420
<ALLOWANCES>                                     1,029
<INVENTORY>                                          0
<CURRENT-ASSETS>                                46,477
<PP&E>                                       1,670,055
<DEPRECIATION>                                 321,020
<TOTAL-ASSETS>                               1,406,553
<CURRENT-LIABILITIES>                          104,760
<BONDS>                                        842,872
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         8,492
<OTHER-SE>                                     411,196
<TOTAL-LIABILITY-AND-EQUITY>                 1,406,553
<SALES>                                              0
<TOTAL-REVENUES>                               386,917
<CGS>                                                0
<TOTAL-COSTS>                                  186,069
<OTHER-EXPENSES>                                45,674
<LOSS-PROVISION>                                   337
<INTEREST-EXPENSE>                              36,434
<INCOME-PRETAX>                                113,017
<INCOME-TAX>                                    41,816
<INCOME-CONTINUING>                             71,201
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                     38
<CHANGES>                                            0
<NET-INCOME>                                    71,163
<EPS-PRIMARY>                                      .89
<EPS-DILUTED>                                      .89