<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM FORM 10
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITY EXCHANGE ACT OF
1934 FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2000 AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-2000             DEC-31-2000
<PERIOD-START>                             JUL-01-2000             JAN-01-2000
<PERIOD-END>                               SEP-30-2000             SEP-30-2000
<CASH>                                          11,909                  11,909
<SECURITIES>                                         0                       0
<RECEIVABLES>                                    7,936                   7,936
<ALLOWANCES>                                      (27)                    (27)
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                20,323                  20,323
<PP&E>                                         238,405                 238,405
<DEPRECIATION>                               (166,817)               (166,817)
<TOTAL-ASSETS>                                 103,931                 103,931
<CURRENT-LIABILITIES>                           15,140                  15,140
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                            87                      87
<OTHER-SE>                                      48,366                  48,366
<TOTAL-LIABILITY-AND-EQUITY>                   103,931                 103,931
<SALES>                                         10,956                  26,847
<TOTAL-REVENUES>                                11,787                  28,690
<CGS>                                                0                       0
<TOTAL-COSTS>                                    5,365                  14,034
<OTHER-EXPENSES>                                     0                       0
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                 813                   2,831
<INCOME-PRETAX>                                  5,861                  12,642
<INCOME-TAX>                                     2,597                   5,296
<INCOME-CONTINUING>                              3,264                   7,346
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                     242
<CHANGES>                                            0                       0
<NET-INCOME>                                     3,264                   7,104
<EPS-BASIC>                                       0.38                    0.82
<EPS-DILUTED>                                     0.37                    0.81


</TABLE>