<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM MESA OFFSHORE TRUST FORM 10-Q FOR THE QUARTERLY PERIOD ENDED 9/30/99 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-END> SEP-30-1999 <CASH> 2,455,079 <SECURITIES> 0 <RECEIVABLES> 23,872 <ALLOWANCES> 0 <INVENTORY> 0 <CURRENT-ASSETS> 0 <PP&E> 380,905,000 <DEPRECIATION> 380,868,692 <TOTAL-ASSETS> 2,515,259 <CURRENT-LIABILITIES> 570,680 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 0 <OTHER-SE> 1,944,579 <TOTAL-LIABILITY-AND-EQUITY> 2,515,259 <SALES> 2,876,656 <TOTAL-REVENUES> 2,948,955 <CGS> 0 <TOTAL-COSTS> 0 <OTHER-EXPENSES> 419,426 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 2,529,529 <INCOME-TAX> 0 <INCOME-CONTINUING> 2,529,529 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 2,529,529 <EPS-BASIC> .03 <EPS-DILUTED> .03