RVEP Rio Vista Energy Partners L.P. (MM)

CUSIP No. 767271109 13G Page 2 of 7 Pages
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 (1) NAMES OF REPORTING PERSONS
 I.R.S. IDENTIFICATION NO.
 OF ABOVE PERSONS (ENTITIES ONLY)
 Ensign Peak Advisors, Inc
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 (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
 (a) [ ]
 (b) [ ]
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 (3) SEC USE ONLY
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 (4) CITIZENSHIP OR PLACE OF ORGANIZATION
 Utah Corporation
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NUMBER OF (5) SOLE VOTING POWER
 -0-
SHARES ----------------------------------------------------------------

BENEFICIALLY (6) SHARED VOTING POWER
 27,262
OWNED BY ----------------------------------------------------------------

EACH (7) SOLE DISPOSITIVE POWER
 -0-
REPORTING ----------------------------------------------------------------

PERSON WITH (8) SHARED DISPOSITIVE POWER
 27,262
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 (9) AGGREGATE AMOUNT BENEFICIALLY OWNED
 BY EACH REPORTING PERSON
 27,262
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 (10) CHECK BOX IF THE AGGREGATE AMOUNT
 IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ]
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 (11) PERCENT OF CLASS REPRESENTED
 BY AMOUNT IN ROW (9)
 0.97%
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 (12) TYPE OF REPORTING PERSON **
 CO
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 ** SEE INSTRUCTIONS BEFORE FILLING OUT!

CUSIP No. 767271109 13G Page 3 of 7 Pages

Item 1(a). Name of Issuer:

 RIO VISTA ENERGY PARTNERS L.P. (the "Issuer").

Item 1(b). Address of Issuer's Principal Executive Offices:

 1313 E. Alton Gloor Blvd., Suite J, Brownsville, Texas 78526

Item 2(a). Name of Person Filing:

 Ensign Peak Advisors, Inc


Item 2(b). Address of Principal Business Office or, if None, Residence:

 50 East North Temple, Room 1560
 Salt Lake City, Utah 84150

Item 2(c). Citizenship:

 Ensign Peak Advisors, Inc
 50 East North Temple, Room 1560
 Salt Lake City, Utah 84150
 (a Utah Corporation)

Item 2(d). Title of Class of Securities:

 Common Stock

Item 2(e). CUSIP Number:

 767271109

CUSIP No. 767271109 13G Page 4 of 7 Pages

Item 3. If this statement is filed pursuant to Rules 13d-1(b) or 13d-2(b) or
(c), check whether the person filing is a:

 (a) [ ] Broker or dealer registered under Section 15 of the Act,

 (b) [ ] Bank as defined in Section 3(a)(6) of the Act,

 (c) [ ] Insurance Company as defined in Section 3(a)(19) of the
 Act,

 (d) [ ] Investment Company registered under Section 8 of the
 Investment Company Act of 1940,

 (e) [ ] Investment Adviser in accordance with Rule
 13d-1(b)(1)(ii)(E),

 (f) [ ] Employee Benefit Plan or Endowment Fund in accordance
 with Rule 13d-1(b)(1)(ii)(F),

 (g) [ ] Parent Holding Company or control person in accordance
 with Rule 13d-1(b)(1)(ii)(G),

 (h) [ ] Savings Association as defined in Section 3(b) of the
 Federal Deposit Insurance Act,

 (i) [ ] Church Plan that is excluded from the definition of an
 investment company under Section 3(c)(14) of the Investment
 Company Act of 1940,

 (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(c), check the box. [X]

CUSIP No. 767271109 13G Page 5 of 7 Pages

Item 4. Ownership.

 Ensign Peak Advisors, Inc

 (a) Amount beneficially owned:
 27,262 **

 (b) Percent of class:
 0.97% **

 (c) Number of shares as to which such person has:

 (i) Sole power to vote or direct the vote:
 None

 (ii) Shared power to vote or direct the vote:
 27,262 **

 (iii) Sole power to dispose or direct the disposition:
 None

 (iv) Shared power to dispose or direct the disposition:
 27,262 **


Item 5. Ownership of Five Percent or Less of a Class.

 If this statement is being filed to report the fact that as of the
 date hereof the reporting person has ceased to be the beneficial
 owner of more than 5 percent of the class of securities, check the
 following [X].

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

 Not applicable.


Item 7. Identification and Classification of the Subsidiary Which Acquired
 the Security Being Reported on by the Parent Holding Company.

 Not applicable.

CUSIP No. 767271109 13G Page 6 of 7 Pages


Item 8. Identification and Classification of Members of the Group.

 Not applicable.


Item 9. Notice of Dissolution of Group.

 Not applicable.

_______________________________________________________________

** Ownership is calculated on the basis of the currently exercisable
 portion of a warrant issued by the Issuer to TCW Energy Funds X
 Holdings, L.P. ("Holdings"). Ensign Peak Advisors ("Ensign Peak")
 holds a 6.81556% equity interest in Holdings.

 TCW Asset Management Company ("TAMCO") serves as discretionary
 investment manager to Ensign Peak with regard to its investment in
 Holdings pursuant to the Amended and Restated Investment Management
 and Custody Agreement between Ensign Peak Advisors and TAMCO, dated
 December 3, 2003. If the warrant were exercised, Ensign Peak and
 TAMCO would have shared power to vote (or direct the vote) and
 dispose of (or direct the disposition of) common units of Rio Vista.

 TAMCO has advised us that the warrant provides that Holdings may,
 until a demand loan ("Demand Loan") advanced by a member company of
 the TCW Business Unit is repaid in full, purchase Common Units in
 the Issuer in an amount determined by dividing the outstanding
 principal amount then owed on the Demand Loan by an exercise price
 equal to the lower of: (A) $13.33 per Common Unit and (B) 90%
 multiplied by the average of the closing prices for a Common Unit
 for the 20 trading days immediately preceding the date of Holdings'
 election to exercise. In addition pursuant to the term of the
 warrant, Holdings has the right to exercise the warrant to
 effectively convert debt owed by the Issuer under a senior credit
 facility ("Credit Facility"), net of the Demand Loan, but including
 accrued interest and expenses on the remaining principal amount,
 into additional Common Units of the Issuer at a price equal to 90%
 of the 20-day average trading price of such units preceding the
 election to convert. TAMCO has advised us that, as of February 28,
 2009 Holdings and the Issuer agreed to certain modifications
 involving the Demand Loan and the Credit Facility. According to
 TAMCO, these modifications include, among other provisions, a
 limitation on Holding's right to exercise its warrant with respect
 to either the Demand Loan or the amounts due under the Credit
 Facility. In particular, Holdings has agreed that it will not
 (except as to the right to immediately exercise the warrant to
 acquire up to 400,000 Units) exercise any right to acquire Units
 under the terms of the warrant except upon prior written notice to
 the Issuer of not less than sixty-two days. Solely as a result of
 this modification (and not as the result of any purchases or sales
 of Units or rights to Units), Ensign Peak's indirect beneficial
 ownership interest (through Holdings) in the Units of the Issuer
 (as calculated pursuant to Rule 13d-3) has been reduced to 0.97% as
 reported herein.



<PAGE)


CUSIP No. 767271109 13G Page 7 of 7 Pages

Item 10. Certification.

 Because this statement is filed pursuant to Rule 13d-1(b), the
 following certification is included:

 By signing below I certify that, to the best of my knowledge and
 belief, the securities referred to above were not acquired and are
 not held for the purpose of or with the effect of changing or
 influencing the control of the issuer of the securities and were not
 acquired and are not held in connection with or as a participant in
 any transaction having that purpose or effect.



 SIGNATURES

 After reasonable inquiry and to the best of our knowledge and belief, the
undersigned certify that the information set forth in this statement is true,
complete and correct.

DATED: March 11, 2009


 Ensign Peak Advisors, Inc

 By: /s/ Edwin Dennis
 -----------------------------------------------
 Edwin Dennis
 Authorized Signatory