<ARTICLE>                                            5
<LEGEND>
The schedule contains summary financial information extracted from the
condensed balance sheet as of March 31, 1999 and the condensed statement
of income for the three months ended March 31, 1999 and is qualified in its
entirety by reference to such financial statements.
</LEGEND>
<MULTIPLIER>                                      1000
       
                                                
<PERIOD-TYPE>                                    3-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               MAR-31-1999
<CASH>                                             984
<SECURITIES>                                    16,500
<RECEIVABLES>                                  126,135
<ALLOWANCES>                                     6,891
<INVENTORY>                                     36,868
<CURRENT-ASSETS>                               200,045
<PP&E>                                       1,793,957
<DEPRECIATION>                                 853,556
<TOTAL-ASSETS>                               1,533,541
<CURRENT-LIABILITIES>                          145,678 
<BONDS>                                        245,659
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        35,527
<OTHER-SE>                                     641,991
<TOTAL-LIABILITY-AND-EQUITY>                 1,533,541
<SALES>                                        191,018
<TOTAL-REVENUES>                               197,442
<CGS>                                          144,649
<TOTAL-COSTS>                                  144,649
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               4,527
<INCOME-PRETAX>                                 25,141
<INCOME-TAX>                                     9,303
<INCOME-CONTINUING>                             15,838
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    15,838
<EPS-PRIMARY>                                     0.36
<EPS-DILUTED>                                     0.36