<ARTICLE>                                          5
<MULTIPLIER>                                   1,000

                                              
<PERIOD-TYPE>                                 12-MOS
<FISCAL-YEAR-END>                        DEC-31-1999
<PERIOD-END>                             DEC-31-1999
<CASH>                                       (5,467)
<SECURITIES>                                   8,800
<RECEIVABLES>                                144,371
<ALLOWANCES>                                   7,734
<INVENTORY>                                   15,927
<CURRENT-ASSETS>                             202,450
<PP&E>                                     1,748,586
<DEPRECIATION>                               819,959
<TOTAL-ASSETS>                             1,561,460
<CURRENT-LIABILITIES>                        142,645
<BONDS>                                      277,570
<PREFERRED-MANDATORY>                              0
<PREFERRED>                                        0
<COMMON>                                      34,933
<OTHER-SE>                                   636,030
<TOTAL-LIABILITY-AND-EQUITY>               1,561,460
<SALES>                                      937,645
<TOTAL-REVENUES>                             959,272
<CGS>                                        738,249
<TOTAL-COSTS>                                738,249
<OTHER-EXPENSES>                                   0
<LOSS-PROVISION>                                   0
<INTEREST-EXPENSE>                            17,774
<INCOME-PRETAX>                               95,540
<INCOME-TAX>                                  32,961
<INCOME-CONTINUING>                           62,579
<DISCONTINUED>                                     0
<EXTRAORDINARY>                                    0
<CHANGES>                                          0
<NET-INCOME>                                  62,579
<EPS-BASIC>                                   1.45
<EPS-DILUTED>                                   1.45