<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM FORM 10Q
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITY
EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 1997 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-31-1997             DEC-31-1997
<PERIOD-START>                             JUL-01-1997             JAN-01-1997
<PERIOD-END>                               SEP-30-1997             SEP-30-1997
<CASH>                                          10,892                  10,892
<SECURITIES>                                         0                       0
<RECEIVABLES>                                    5,470                   5,470
<ALLOWANCES>                                      (50)                    (50)
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                                16,695                  16,695
<PP&E>                                         214,775                 214,775
<DEPRECIATION>                                (99,443)                (99,443)
<TOTAL-ASSETS>                                 132,388                 132,388
<CURRENT-LIABILITIES>                           13,920                  13,920
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                            86                      86
<OTHER-SE>                                      66,865                  66,865
<TOTAL-LIABILITY-AND-EQUITY>                   132,388                 132,388
<SALES>                                          8,377                  24,478
<TOTAL-REVENUES>                                 8,738                  25,718
<CGS>                                                0                       0
<TOTAL-COSTS>                                    7,514                  21,736
<OTHER-EXPENSES>                                     1                       3
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                 975                   2,565
<INCOME-PRETAX>                                    364                   1,818
<INCOME-TAX>                                       137                     372
<INCOME-CONTINUING>                                  0                       0
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                       227                   1,446
<EPS-PRIMARY>                                      .03                     .17
<EPS-DILUTED>                                      .03                     .17
        

</TABLE>