<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED FINANCIAL STATEMENTS OF THE COMPANY AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997             DEC-31-1996
<PERIOD-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997             JAN-01-1996
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997             DEC-31-1996
<CASH>                                           4,194                     655                   1,146                   6,290
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                    8,416                   9,220                   9,991                   9,464
<ALLOWANCES>                                         0                       0                       0                       0
<INVENTORY>                                          0                       0                       0                       0
<CURRENT-ASSETS>                                13,033                  10,360                  11,884                  16,020
<PP&E>                                         210,800                 227,449                 239,696                 195,963
<DEPRECIATION>                                  10,184                  15,545                  21,263                   5,624
<TOTAL-ASSETS>                                 214,406                 222,958                 231,038                 207,179
<CURRENT-LIABILITIES>                           10,367                  11,463                   9,614                   7,896
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                           339                     339                     339                     339
<OTHER-SE>                                     190,402                 193,391                 197,221                 186,847
<TOTAL-LIABILITY-AND-EQUITY>                   214,406                 222,958                 231,038                 207,179
<SALES>                                         18,036                  34,239                  52,110                  23,968
<TOTAL-REVENUES>                                18,036                  34,239                  52,110                  23,968
<CGS>                                                0                       0                       0                       0
<TOTAL-COSTS>                                   14,350                  27,693                  41,323                  19,281
<OTHER-EXPENSES>                                   (59)                    (97)                   (134)                   (359)
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                                 242                     486                     825                   2,965
<INCOME-PRETAX>                                  3,503                   6,157                  10,096                   2,081
<INCOME-TAX>                                     1,226                   2,155                   3,534                   3,484
<INCOME-CONTINUING>                              2,277                   4,002                   6,562                  (1,403)
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                     2,277                   4,002                   6,562                  (1,403)
<EPS-PRIMARY>                                      .07                     .12                     .19                    (.07)
<EPS-DILUTED>                                      .06                     .11                     .18                    (.07)


</TABLE>