<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE 
STATEMENT OF INCOME FOR THE YEAR ENDED DECEMBER 31, 1997 AND THE BALANCE SHEET
AT DECEMBER 31, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               DEC-31-1997
<CASH>                                           7,134
<SECURITIES>                                         0
<RECEIVABLES>                                  140,657
<ALLOWANCES>                                     7,721
<INVENTORY>                                      1,929
<CURRENT-ASSETS>                               168,088
<PP&E>                                       1,652,123
<DEPRECIATION>                                 849,599
<TOTAL-ASSETS>                                 987,818
<CURRENT-LIABILITIES>                          255,628
<BONDS>                                        227,769
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       191,968
<OTHER-SE>                                     123,096
<TOTAL-LIABILITY-AND-EQUITY>                   987,818
<SALES>                                              0
<TOTAL-REVENUES>                               611,222
<CGS>                                                0
<TOTAL-COSTS>                                  517,275
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              18,932
<INCOME-PRETAX>                                 75,577
<INCOME-TAX>                                    30,272
<INCOME-CONTINUING>                             45,305
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    45,305
<EPS-PRIMARY>                                        0
<EPS-DILUTED>                                        0