<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM ANNUAL
REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934
FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997
<PERIOD-START>                             OCT-01-1997             JAN-01-1997
<PERIOD-END>                               DEC-31-1997             DEC-31-1997
<CASH>                                           9,391                   9,391
<SECURITIES>                                         0                       0
<RECEIVABLES>                                    6,658                   6,658
<ALLOWANCES>                                      (50)                    (50)
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                16,336                  16,336
<PP&E>                                         217,913                 217,913
<DEPRECIATION>                               (103,644)               (106,644)
<TOTAL-ASSETS>                                 130,924                 130,924
<CURRENT-LIABILITIES>                           13,698                  13,698
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                            86                      86
<OTHER-SE>                                      66,471                  66,471
<TOTAL-LIABILITY-AND-EQUITY>                   130,924                 130,924
<SALES>                                          9,024                  33,502
<TOTAL-REVENUES>                                 9,376                  35,094
<CGS>                                                0                       0
<TOTAL-COSTS>                                    8,335                  30,071
<OTHER-EXPENSES>                                    44                      47
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                 963                   3,528
<INCOME-PRETAX>                                    188                   2,006
<INCOME-TAX>                                     (236)                     136
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                       424                   1,870
<EPS-PRIMARY>                                      .05                     .22
<EPS-DILUTED>                                      .05                     .22


</TABLE>