<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED FINANCIAL STATEMENTS AS OF AND FOR THE NINE MONTHS ENDED
SEPTEMBER 30, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FORM 10-Q FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 1997.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               SEP-30-1997
<CASH>                                           2,904
<SECURITIES>                                         0
<RECEIVABLES>                                  155,869
<ALLOWANCES>                                    15,829
<INVENTORY>                                          0
<CURRENT-ASSETS>                               169,243
<PP&E>                                         677,635
<DEPRECIATION>                                 129,308
<TOTAL-ASSETS>                                 916,027
<CURRENT-LIABILITIES>                          140,050
<BONDS>                                        260,365
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           489
<OTHER-SE>                                     428,679
<TOTAL-LIABILITY-AND-EQUITY>                   916,027
<SALES>                                              0
<TOTAL-REVENUES>                               660,874
<CGS>                                                0
<TOTAL-COSTS>                                  523,097
<OTHER-EXPENSES>                                27,303
<LOSS-PROVISION>                                 6,418
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                 74,595
<INCOME-TAX>                                    22,901
<INCOME-CONTINUING>                             51,694
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    51,694
<EPS-PRIMARY>                                     1.10
<EPS-DILUTED>                                     1.10