<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from Form 10-Q as
of March 31, 1997 and is qualified in its entirety by reference to such
financial statements.
</LEGEND>
<RESTATED> 
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               MAR-31-1997
<CASH>                                               0
<SECURITIES>                                         0
<RECEIVABLES>                                   95,419<F1>
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                               155,797
<PP&E>                                         598,387
<DEPRECIATION>                               (169,691)
<TOTAL-ASSETS>                                 976,837
<CURRENT-LIABILITIES>                          209,292
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           779
<OTHER-SE>                                     455,277
<TOTAL-LIABILITY-AND-EQUITY>                   976,837
<SALES>                                              0
<TOTAL-REVENUES>                               314,650
<CGS>                                                0
<TOTAL-COSTS>                                  255,074
<OTHER-EXPENSES>                                18,674
<LOSS-PROVISION>                                     0 
<INTEREST-EXPENSE>                               6,730
<INCOME-PRETAX>                                 34,172
<INCOME-TAX>                                    13,669
<INCOME-CONTINUING>                             20,503
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    20,503
<EPS-PRIMARY>                                     0.24
<EPS-DILUTED>                                     0.24
<FN>
<F1>Trade Accounts Receivable, Less Allowance for Doubtful Accounts
</FN>