<ARTICLE> 5
<MULTIPLIER> 1,000
       
                                                  
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1996
<PERIOD-START>                             JAN-01-1997             JAN-01-1996
<PERIOD-END>                               SEP-30-1997             SEP-30-1996
<CASH>                                             150                     655
<SECURITIES>                                    15,967                  30,211
<RECEIVABLES>                                   45,486                  33,472
<ALLOWANCES>                                         0                       0
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<CURRENT-ASSETS>                                92,965                  88,033
<PP&E>                                         251,243                 243,014
<DEPRECIATION>                               (176,865)               (177,021)
<TOTAL-ASSETS>                                 209,294                 185,925
<CURRENT-LIABILITIES>                           29,461                  18,648
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                         6,792                   6,792
<OTHER-SE>                                           0                       0
<TOTAL-LIABILITY-AND-EQUITY>                   209,294                 185,925
<SALES>                                         78,840                 207,621
<TOTAL-REVENUES>                                78,840                 207,621
<CGS>                                           65,080                 173,665
<TOTAL-COSTS>                                   65,080                 173,665
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   0                       0
<INCOME-PRETAX>                                    317                   1,408
<INCOME-TAX>                                     2,481                   5,385
<INCOME-CONTINUING>                              4,607                  10,000
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                     4,607                  10,000
<EPS-PRIMARY>                                      .70                    1.53
<EPS-DILUTED>                                      .69                    1.50