**Exhibit
      31.2**


**CERTIFICATION**





I,
      Ian T.
      Bothwell, Chief Financial Officer, certify that:





1.  I
      have
      reviewed this report on Form 10-Q of Rio Vista Energy Partners L.P.





2.  Based
      on
      my knowledge, this report does not contain any untrue statement of material
      fact
      or omit to state a material fact necessary to make the statements made, in
      light
      of the circumstances under which such statements were made, not misleading
      with
      respect to the period covered by this report;





3.  Based
      on
      my knowledge, the financial statements, and other financial information included
      in this report, fairly present in all material respects the financial condition,
      results of operations and cash flows of the registrant as of, and for, the
      periods presented in this report;





4.
       The registrant's other certifying officer and I are responsible for
      establishing and maintaining disclosure controls and procedures (as defined
      in
      Exchange Act Rules 13a-15(e) for the registrant and have:





a)
       Designed such disclosure controls and procedures, or caused such
      disclosure controls and procedures to be designed under our supervision, to
      ensure that material information relating to the registrant, including its
      consolidated subsidiaries, is made known to us by others within those entities,
      particularly during the period in which this report is being prepared;





b)
       Evaluated the effectiveness of the registrant’s disclosure controls and
      procedures and presented in this report our conclusions about the effectiveness
      of the disclosure controls and procedures, as of the end of the period covered
      by this report based on such evaluation; and





c)
       Disclosed in this report any change in the registrant’s internal control
      over financial reporting that occurred during the registrant’s most recent
      fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual
      report) that has materially affected, or is reasonably likely to materially
      affect, the registrant’s internal control over financial reporting;
      and





5.
       The registrant's other certifying officer and I have disclosed, based on
      our most recent evaluation of internal control over financial reporting, to
      the
      registrant's auditors and the audit committee of registrant's board of
      managers:





a)
       All significant deficiencies and material weaknesses in the design or
      operation of internal control over financial reporting which are reasonably
      likely to adversely affect the registrant’s ability to record, process,
      summarize and report financial information; and





b) 
      Any fraud, whether or not material, that involves management or other employees
      who have a significant role in the registrant’s internal control over financial
      reporting.







Date:
      May
      22, 2006


/s/
                Ian T. BothwellIan
                T. Bothwell
              Chief
                Financial Officer (principal
              accounting
                and financial officer) of Rio
              Vista
                GP LLC, the general partner of Rio
              Vista
                Energy Partners L.P.