<ARTICLE>                                            5
<LEGEND>
The schedule contains summary financial information extracted from the
condensed balance sheet as of June 30, 2000 and the condensed statement of
income for the six months ended June 30, 2000 and is qualified in its
entirety by reference to such financial statements.

<MULTIPLIER>                                      1000

                                                
<PERIOD-TYPE>                                    6-MOS
<FISCAL-YEAR-END>                          DEC-31-2000
<PERIOD-END>                               JUN-30-2000
<CASH>                                         (5,970)
<SECURITIES>                                     5,000
<RECEIVABLES>                                  144,421
<ALLOWANCES>                                     8,375
<INVENTORY>                                     15,743
<CURRENT-ASSETS>                               185,841
<PP&E>                                       1,782,077
<DEPRECIATION>                                 841,808
<TOTAL-ASSETS>                               1,573,373
<CURRENT-LIABILITIES>                          141,413
<BONDS>                                        329,249
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        33,307
<OTHER-SE>                                     612,728
<TOTAL-LIABILITY-AND-EQUITY>                 1,573,373
<SALES>                                        485,124
<TOTAL-REVENUES>                               496,259
<CGS>                                          371,477
<TOTAL-COSTS>                                  371,477
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              11,306
<INCOME-PRETAX>                                 86,100
<INCOME-TAX>                                    23,758
<INCOME-CONTINUING>                             54,674
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    54,674
<EPS-BASIC>                                     1.32
<EPS-DILUTED>                                     1.32