<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
STATEMENT OF INCOME FOR THE THREE MONTHS ENDED MARCH 31, 1997 AND THE BALANCE
SHEET AS OF MARCH 31, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               MAR-31-1997
<CASH>                                           9,773
<SECURITIES>                                         0
<RECEIVABLES>                                  155,978
<ALLOWANCES>                                     9,220
<INVENTORY>                                      1,534
<CURRENT-ASSETS>                               182,647
<PP&E>                                       1,551,734
<DEPRECIATION>                                 771,263
<TOTAL-ASSETS>                                 970,734
<CURRENT-LIABILITIES>                          253,687
<BONDS>                                        227,737
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       191,968
<OTHER-SE>                                      90,835
<TOTAL-LIABILITY-AND-EQUITY>                   970,734
<SALES>                                              0
<TOTAL-REVENUES>                               149,646
<CGS>                                                0
<TOTAL-COSTS>                                  124,115
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               4,877
<INCOME-PRETAX>                                 20,398
<INCOME-TAX>                                     8,433
<INCOME-CONTINUING>                             11,965
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    11,965
<EPS-PRIMARY>                                        0
<EPS-DILUTED>                                        0