<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-31-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                           8,238
<SECURITIES>                                    13,753
<RECEIVABLES>                                   51,722
<ALLOWANCES>                                       557
<INVENTORY>                                     13,098
<CURRENT-ASSETS>                                93,384
<PP&E>                                         476,041
<DEPRECIATION>                                 228,118
<TOTAL-ASSETS>                                 361,397
<CURRENT-LIABILITIES>                           61,471
<BONDS>                                        106,302
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                         3,091
<OTHER-SE>                                     143,199
<TOTAL-LIABILITY-AND-EQUITY>                   361,397
<SALES>                                         42,877
<TOTAL-REVENUES>                               243,888
<CGS>                                           32,863
<TOTAL-COSTS>                                  158,370
<OTHER-EXPENSES>                                52,418
<LOSS-PROVISION>                                  (70)
<INTEREST-EXPENSE>                               7,403
<INCOME-PRETAX>                                 28,104
<INCOME-TAX>                                    10,637
<INCOME-CONTINUING>                             17,467
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    17,467
<EPS-BASIC>                                        .87
<EPS-DILUTED>                                      .86