<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM APPLICABLE
FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               JUN-30-1999
<CASH>                                         129,566
<SECURITIES>                                         0
<RECEIVABLES>                                   29,404
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                               172,595
<PP&E>                                       1,137,337
<DEPRECIATION>                               (696,626)
<TOTAL-ASSETS>                                 643,547
<CURRENT-LIABILITIES>                           49,491
<BONDS>                                        212,204
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                         16
<COMMON>                                           425
<OTHER-SE>                                     336,517
<TOTAL-LIABILITY-AND-EQUITY>                   643,547
<SALES>                                              0
<TOTAL-REVENUES>                                83,538
<CGS>                                                0
<TOTAL-COSTS>                                  122,530
<OTHER-EXPENSES>                                 (164)
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               8,265
<INCOME-PRETAX>                               (44,361)
<INCOME-TAX>                                     1,220
<INCOME-CONTINUING>                           (51,403)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                  (51,403)
<EPS-BASIC>                                     (1.22)
<EPS-DILUTED>                                   (1.22)