<ARTICLE> 5
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-2000
<PERIOD-START>                             JAN-01-2000
<PERIOD-END>                               SEP-30-2000
<CASH>                                          28,894
<SECURITIES>                                         0
<RECEIVABLES>                                  258,381
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                                44,199
<PP&E>                                       2,143,526
<DEPRECIATION>                               1,239,623
<TOTAL-ASSETS>                               1,342,292
<CURRENT-LIABILITIES>                          570,183
<BONDS>                                        137,185
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        29,845
<OTHER-SE>                                     415,530
<TOTAL-LIABILITY-AND-EQUITY>                 1,342,292
<SALES>                                              0
<TOTAL-REVENUES>                             2,705,150
<CGS>                                                0
<TOTAL-COSTS>                                2,590,499
<OTHER-EXPENSES>                                 6,627
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              15,071
<INCOME-PRETAX>                                 92,953
<INCOME-TAX>                                    39,412
<INCOME-CONTINUING>                             53,541
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    53,541
<EPS-BASIC>                                       2.15
<EPS-DILUTED>                                     2.14