<ARTICLE> 5
<LEGEND>
This schedule contains summary financial information extracted from the
June 30, 1997 quarterly consolidated financial statements and is qualfied
in its entirety by reference to such financial statements.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               JUN-30-1997
<CASH>                                           4,062
<SECURITIES>                                         0
<RECEIVABLES>                                   80,633
<ALLOWANCES>                                     1,542
<INVENTORY>                                      2,370
<CURRENT-ASSETS>                               107,947
<PP&E>                                         662,223
<DEPRECIATION>                                 204,542
<TOTAL-ASSETS>                                 568,602
<CURRENT-LIABILITIES>                           78,343
<BONDS>                                        219,451
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           314
<OTHER-SE>                                     215,755
<TOTAL-LIABILITY-AND-EQUITY>                   568,602
<SALES>                                              0
<TOTAL-REVENUES>                               412,140
<CGS>                                                0
<TOTAL-COSTS>                                  390,166
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0<F1>
<INTEREST-EXPENSE>                               8,260
<INCOME-PRETAX>                                 13,888
<INCOME-TAX>                                     5,444
<INCOME-CONTINUING>                              8,444
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     8,444
<EPS-PRIMARY>                                      .27
<EPS-DILUTED>                                      .27
<FN>
<F1>Provision for Doubtful accounts included in costs and expenses applicable
to revenues.
</FN>