
<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
COMPANY'S UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS FOR THE SIX MONTHS ENDED
JUNE 30, 1998, 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-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               JUN-30-1998
<CASH>                                           1,464
<SECURITIES>                                         0
<RECEIVABLES>                                    8,043
<ALLOWANCES>                                         0
<INVENTORY>                                        458
<CURRENT-ASSETS>                                14,214
<PP&E>                                         255,677
<DEPRECIATION>                                  62,903
<TOTAL-ASSETS>                                 207,026
<CURRENT-LIABILITIES>                           19,923
<BONDS>                                         56,500
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           141
<OTHER-SE>                                     123,052
<TOTAL-LIABILITY-AND-EQUITY>                   207,026
<SALES>                                         22,151
<TOTAL-REVENUES>                                22,164
<CGS>                                            5,031
<TOTAL-COSTS>                                   19,860
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 788
<INCOME-PRETAX>                                  1,516
<INCOME-TAX>                                       531
<INCOME-CONTINUING>                                985
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                       985
<EPS-PRIMARY>                                      .07
<EPS-DILUTED>                                      .07
        

</TABLE>
