<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEET AT MARCH 31, 1997, JUNE 30, 1997 AND SEPTEMBER 30, 1997 (UNAUDITED) AND
THE STATEMENTS OF OPERATIONS FOR THE QUARTERLY PERIOD ENDED MARCH 31, 1997, JUNE
30, 1997 AND SEPTEMBER 30, 1997 (UNAUDITED) AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS INCLUDED AS PART OF ITS QUARTERLY REPORT
ON FORM 10-Q FOR THE RESPECTIVE PERIODS THEN ENDED.
</LEGEND>

<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-START>                             JAN-01-1997             JAN-01-1997             JAN-01-1997
<PERIOD-END>                               MAR-31-1997             JUN-30-1997             SEP-30-1997
<CASH>                                       3,756,930               3,700,981               3,965,649
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                2,718,929               2,768,091               3,127,523
<ALLOWANCES>                                         0                       0                       0
<INVENTORY>                                          0                       0                       0
<CURRENT-ASSETS>                             6,475,859               6,469,172               7,093,172
<PP&E>                                     124,283,349             124,153,386             124,252,743
<DEPRECIATION>                              15,060,037              16,852,011              18,640,518
<TOTAL-ASSETS>                             117,387,823             115,310,206             114,096,263
<CURRENT-LIABILITIES>                                0                       0                       0
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                             0                       0                       0
<OTHER-SE>                                 117,387,823             115,310,206             114,096,263
<TOTAL-LIABILITY-AND-EQUITY>               117,387,823             115,310,206             114,096,263
<SALES>                                              0                       0                       0
<TOTAL-REVENUES>                             3,141,734               6,381,050              10,163,705
<CGS>                                                0                       0                       0
<TOTAL-COSTS>                                1,985,768               4,005,652               6,003,098
<OTHER-EXPENSES>                                     0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                   0                       0                       0
<INCOME-PRETAX>                                      0                       0                       0
<INCOME-TAX>                                         0                       0                       0
<INCOME-CONTINUING>                                  0                       0                       0
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                 1,242,623               2,489,858               4,381,203
<EPS-PRIMARY>                                        0                       0                       0
<EPS-DILUTED>                                        0                       0                       0


</TABLE>