<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>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-END>                               SEP-30-1997
<CASH>                                           3,105
<SECURITIES>                                    21,006
<RECEIVABLES>                                   80,967
<ALLOWANCES>                                       681
<INVENTORY>                                     17,398
<CURRENT-ASSETS>                               139,015
<PP&E>                                         531,342
<DEPRECIATION>                                 220,699
<TOTAL-ASSETS>                                 524,433
<CURRENT-LIABILITIES>                           87,965
<BONDS>                                        164,968
<PREFERRED-MANDATORY>                            3,091
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                     212,367
<TOTAL-LIABILITY-AND-EQUITY>                   524,433
<SALES>                                         51,229
<TOTAL-REVENUES>                               302,968
<CGS>                                           36,230
<TOTAL-COSTS>                                  202,807
<OTHER-EXPENSES>                                65,923
<LOSS-PROVISION>                                     3
<INTEREST-EXPENSE>                              10,117
<INCOME-PRETAX>                                 30,027
<INCOME-TAX>                                    11,234
<INCOME-CONTINUING>                             18,793
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    18,793
<EPS-PRIMARY>                                      .76
<EPS-DILUTED>                                      .76