<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CONDENSED
CONSOLIDATED BALANCE SHEETS AND STATEMENTS OF EARNINGS 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>                                           1,898
<SECURITIES>                                    16,330
<RECEIVABLES>                                   65,211
<ALLOWANCES>                                       567
<INVENTORY>                                     10,064
<CURRENT-ASSETS>                               106,481
<PP&E>                                         514,468
<DEPRECIATION>                                 188,085
<TOTAL-ASSETS>                                 501,407
<CURRENT-LIABILITIES>                           71,628
<BONDS>                                        159,984
<COMMON>                                         3,091
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<OTHER-SE>                                     213,929
<TOTAL-LIABILITY-AND-EQUITY>                   501,407
<SALES>                                         22,937
<TOTAL-REVENUES>                               190,804
<CGS>                                           18,287
<TOTAL-COSTS>                                  124,027
<OTHER-EXPENSES>                                42,267
<LOSS-PROVISION>                                    64
<INTEREST-EXPENSE>                               6,476
<INCOME-PRETAX>                                 21,299
<INCOME-TAX>                                     7,833
<INCOME-CONTINUING>                             13,466
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    13,466
<EPS-PRIMARY>                                      .51
<EPS-DILUTED>                                      .51