<TABLE> <S> <C>

<ARTICLE> 5
<RESTATED>
<MULTIPLIER> 1,000

<S>                                        <C>                     <C>                     <C>
<PERIOD-TYPE>                                3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997             DEC-31-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                           8,201                   7,177                   2,118
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                   10,594                  14,593                  12,827
<ALLOWANCES>                                       121                     121                     121
<INVENTORY>                                          0                       0                       0
<CURRENT-ASSETS>                                20,854                  24,459                  17,762
<PP&E>                                         325,344                 349,003                 376,997
<DEPRECIATION>                                 101,497                 108,392                 115,003
<TOTAL-ASSETS>                                 246,004                 226,437                 281,434
<CURRENT-LIABILITIES>                           29,800                  40,007                  40,498
<BONDS>                                         38,700                  46,500                  60,000
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                           336                     336                     336
<OTHER-SE>                                     177,168                 179,594                 180,600
<TOTAL-LIABILITY-AND-EQUITY>                   246,004                 266,437                 281,434
<SALES>                                         16,421                  29,528                  41,793
<TOTAL-REVENUES>                                16,660                  29,899                  42,262
<CGS>                                            7,858                  16,359                  24,638
<TOTAL-COSTS>                                    7,858                  16,359                  24,638
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                 866                   1,863                   3,197
<INCOME-PRETAX>                                  5,644                   7,660                   8,536
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                              5,644                   7,660                   8,536
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                     3,652                   4,941                   5,485
<EPS-PRIMARY>                                     0.17                    0.23                    0.26
<EPS-DILUTED>                                     0.16                    0.22                    0.24


</TABLE>