<ARTICLE> 5
       
                                                                                               
<PERIOD-TYPE>                   3-MOS             3-MOS             3-MOS           3-MOS            3-MOS
<FISCAL-YEAR-END>               DEC-31-1998       DEC-31-1997       DEC-31-1997     DEC-31-1997      DEC-31-1997
<PERIOD-END>                    MAR-31-1998       MAR-31-1997       JUN-30-1997     SEP-30-1997      DEC-31-1997
<CASH>                                8,639             3,020             4,413           4,765            6,665
<SECURITIES>                              0                 0                 0               0                0
<RECEIVABLES>                         1,247             1,774             1,345           1,361            1,162
<ALLOWANCES>                              0                 0                 0               0                0
<INVENTORY>                               0                 0                 0               0                0
<CURRENT-ASSETS>                          0                 0                 0               0                0
<PP&E>                              334,431           333,863           333,068         333,568          334,395
<DEPRECIATION>                      156,799           152,380           152,068         153,720          155,367
<TOTAL-ASSETS>                      210,137           208,364           207,814         206,653          207,134
<CURRENT-LIABILITIES>                     0                 0                 0               0                0
<BONDS>                                   0                 0                 0               0                0
<PREFERRED-MANDATORY>                     0                 0                 0               0                0
<PREFERRED>                               0                 0                 0               0                0
<COMMON>                             32,174            30,444            31,371          31,934           32,711
<OTHER-SE>                              325               308               317             323              330
<TOTAL-LIABILITY-AND-EQUITY>        210,137           208,364           207,814         206,653          207,134
<SALES>                                   0                 0                 0               0                0
<TOTAL-REVENUES>                     13,823            12,908            13,443          13,533           14,015
<CGS>                                     0                 0                 0               0                0
<TOTAL-COSTS>                         9,571             9,623             9,268           9,710            9,996
<OTHER-EXPENSES>                          0                 0                 0               0                0
<LOSS-PROVISION>                          0                 0                 0               0                0
<INTEREST-EXPENSE>                    3,183             3,217             3,239           3,254            3,235
<INCOME-PRETAX>                       1,069                68               936             569              784
<INCOME-TAX>                              0                 0                 0               0                0
<INCOME-CONTINUING>                   1,069                68               936             569              784
<DISCONTINUED>                            0                 0                 0               0                0
<EXTRAORDINARY>                     (1,611)                 0                 0               0                0
<CHANGES>                                 0                 0                 0               0                0
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<EPS-DILUTED>                        (0.31)              0.04              0.54            0.33             0.45