Sec Form 4 Filing - Montierra Minerals & Production, L.P. @ EAGLE ROCK ENERGY PARTNERS L P - 2015-10-08

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Montierra Minerals & Production, L.P. 2. Issuer Name and Ticker or Trading Symbol EAGLE ROCK ENERGY PARTNERS L P [ EROC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 16107 KENSINGTON DRIVE #257 3. Date of Earliest Transaction (MM/DD/YY) 10/08/2015 (Street) SUGAR LAND, TX77479 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 6,224,449 ( 2 ) D 0 D ( 2 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 50,311 ( 3 ) D 0 D ( 3 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 3,004,733 ( 4 ) D 0 D ( 4 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 31,429,939 ( 5 ) D 0 D ( 5 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 54,714 ( 6 ) D 0 D ( 6 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 3,593,475 ( 7 ) D 0 D ( 7 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 7,028,548 ( 8 ) D 0 D ( 8 ) ( 10 ) Common Units Representing Limited Partner Interests 10/08/2015 J( 1 ) 1,954,432 ( 9 ) D 0 D ( 9 ) ( 10 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Montierra Minerals & Production, L.P. 16107 KENSINGTON DRIVE #257 SUGAR LAND, TX77479 X Montierra Management LLC 16107 KENSINGTON DRIVE #257 SUGAR LAND, TX77479 X Natural Gas Partners VII, L.P. 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X Natural Gas Partners VIII, L.P. 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X NGP Income Management, L.L.C. 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X Eagle Rock Holdings NGP7, LLC 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X Eagle Rock Holdings NGP8, LLC 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X ERH NGP 7 SPV, LLC 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X ERH NGP 8 SPV, LLC 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X NGP Income Co-Investment Opportunities Fund II, L.P. 5221 N O?CONNOR BLVD, SUITE 1100 IRVING, TX75039 X Signatures /s/ Joseph A. Mills, Chief Executive Officer of Montierra Management LLC, general partner of Montierra Minerals & Production, L.P. 10/13/2015 Signature of Reporting Person Date /s/ Joseph A. Mills, Chief Executive Officer of Montierra Management LLC 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Authorized Member of GFW VII, L.L.C., general partner of G.F.W. Energy VII, L.P., general partner of Natural Gas Partners VII, L.P. 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Authorized Member of GFW VIII, L.L.C., general partner of G.F.W. Energy VIII, L.P., general partner of Natural Gas Partners VIII, L.P. 10/13/2015 Signature of Reporting Person Date /s/ Tony R. Weber, President of NGP Income Management L.L.C. 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Authorized Member of GFW VII, L.L.C., general partner of G.F.W. Energy VII, L.P., general partner of Natural Gas Partners VII, L.P., sole member of Eagle Rock Holdings NGP 7, LLC 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Authorized Member of GFW VIII, L.L.C., general partner of G.F.W. Energy VIII, L.P., general partner of Natural Gas Partners VIII, L.P., sole member of Eagle Rock Holdings NGP 8, LLC 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Chief Executive Officer & President of ERH NGP 7 SPV, LLC 10/13/2015 Signature of Reporting Person Date /s/ Kenneth A. Hersh, Chief Executive Officer & President of ERH NGP 8 SPV, LLC 10/13/2015 Signature of Reporting Person Date /s/ Tony R. Weber, President of NGP Income Co-Investment II GP, L.L.C., general partner of NGP Income Co-Investment Opportunities Fund II, L.P. 10/13/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On May 21, 2015, the Issuer entered into an Agreement and Plan of Merger (the "Merger Agreement") with Vanguard Natural Resources, LLC ("Vanguard"), pursuant to which Talon Merger Sub, LLC, an indirect wholly owned subsidiary of Vanguard, would merge with and into the Issuer, with the Issuer continuing as the surviving entity and as a wholly owned indirect subsidiary of Vanguard. On October 8, 2015, the transactions contemplated by the Merger Agreement were consummated. As a result, pursuant to the terms of the Merger Agreement, all common units representing limited partner interests in the Issuer ("Common Units") ceased to be listed on the NASDAQ, were deregistered under the Securities Exchange Act of 1934, and were converted into the right of each unitholder to receive a number of Vanguard common units equal to 0.185 multiplied by the number of Common Units held by such unitholder. The Issuer is now an indirect wholly owned subsidiary of Vanguard. ( 2 )Montierra Minerals & Production, L.P. ("Montierra") is the sole record owner of these 6,224,449 Common Units. Because Montierra Management LLC ("Montierra Management") is the general partner of Montierra, Montierra Management may be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 6,224,449 Common Units held by Montierra. Natural Gas Partners VII, L.P. ("NGP VII") appoints three managers on the board of Montierra Management, and NGP VII also owns a majority limited partner interest in Montierra. NGP VII thus may also be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 6,224,449 Common Units held by Montierra. ( 3 )Montierra Management is the sole record owner of these 50,311 Common Units. NGP VII appoints three managers on the board of Montierra Management. NGP VII thus may be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 50,311 Common Units held by Montierra Management. ( 4 )NGP VII is the sole record owner of these 3,004,733 Common Units. ( 5 )Natural Gas Partners VIII, L.P. ("NGP VIII") is the sole record owner of these 31,429,939 Common Units. ( 6 )NGP Income Management, L.L.C. ("NGP Income Management") is the sole record owner of these 54,714 Common Units. Because NGP VII directly owns 100% of NGP Income Management, NGP VII may be deemed to possess voting and sole dispositive power over, and thus beneficial ownership of, the 54,714 Common Units held by NGP Income Management. ( 7 )ERH NGP 7 SPV, LLC ("SPV 7") is the sole record owner of these 3,593,475 Common Units. Eagle Rock Holdings NGP 7, LLC is the sole member of SPV 7 and may be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 3,593,475 Common Units held by SPV 7. Because NGP VII indirectly owns 100% of SPV 7, NGP VII may also be deemed to possess sole voting and dispositive power over, and thus possess beneficial ownership of, the 3,593,475 Common Units held by SPV 7. ( 8 )ERH NGP 8 SPV, LLC ("SPV 8") is the sole record owner of these 7,028,548 Common Units. Eagle Rock Holdings NGP 8, LLC is the sole member of SPV 8 and may be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 7,028,548 Common Units held by SPV 8. Because NGP VIII indirectly owns 100% of SPV 8, NGP VIII may also be deemed to possess sole voting and dispositive power over, and thus beneficial ownership of, the 7,028,548 Common Units held by SPV 8. ( 9 )NGP Income Co-Investment Opportunities Fund II, L.P. ("NGP Co-Invest") is the sole record owner of these 1,954,432 Common Units. ( 10 )NGP Energy Capital Management, L.L.C. ("NGP ECM") does not directly own any Common Units. The ultimate general partners of NGP VII and NGP VIII have delegated full power and authority to manage NGP VII and NGP VIII to NGP ECM. NGP ECM controls NGP Income Co-Investment II GP, L.L.C., the general partner of NGP Co-Invest; thus, NGP ECM has the full power and authority to manage NGP Co-Invest. Thus, NGP ECM may be deemed to possess sole voting and dispositive powers over, and thus beneficial ownership of, all of the 53,340,601 Common Units reported herein.

Remarks: Form 1 of 2.

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