<ARTICLE> 5
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE COMPANY'S
CONSOLIDATED FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1996
<PERIOD-END>                               JUN-30-1996
<CASH>                                          36,509
<SECURITIES>                                         0
<RECEIVABLES>                                   26,333
<ALLOWANCES>                                         0
<INVENTORY>                                      6,286
<CURRENT-ASSETS>                                76,520
<PP&E>                                         549,744
<DEPRECIATION>                               (174,177)
<TOTAL-ASSETS>                                 531,883
<CURRENT-LIABILITIES>                           65,593
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           313
<OTHER-SE>                                     248,802
<TOTAL-LIABILITY-AND-EQUITY>                   531,883
<SALES>                                        257,967
<TOTAL-REVENUES>                               257,967
<CGS>                                                0
<TOTAL-COSTS>                                  219,240
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               9,054
<INCOME-PRETAX>                                 31,393
<INCOME-TAX>                                    12,557
<INCOME-CONTINUING>                             18,836
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    18,836
<EPS-PRIMARY>                                     0.60
<EPS-DILUTED>                                     0.60