<TABLE> <S> <C>
<PAGE>
<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
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<CASH> 18,213
<SECURITIES> 0
<RECEIVABLES> 44,327
<ALLOWANCES> 2,182
<INVENTORY> 0
<CURRENT-ASSETS> 75,014
<PP&E> 1,217,331
<DEPRECIATION> (530,482)
<TOTAL-ASSETS> 790,881
<CURRENT-LIABILITIES> 65,288
<BONDS> 287,829
0
17
<COMMON> 430
<OTHER-SE> 285,993
<TOTAL-LIABILITY-AND-EQUITY> 790,881
<SALES> 0
<TOTAL-REVENUES> 123,147
<CGS> 0
<TOTAL-COSTS> 112,613
<OTHER-EXPENSES> (121)
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 15,958
<INCOME-PRETAX> (4,962)
<INCOME-TAX> 2,300
<INCOME-CONTINUING> (15,200)
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (15,200)
<EPS-BASIC> (0.36)
<EPS-DILUTED> (0.36)
</TABLE>