Exhibit W

AMENDMENT NO. 1 TO JOINT FILING AGREEMENT

The undersigned each agree that the Joint Filing Agreement, dated August 15, 2011 and filed as Exhibit A to the Schedule 13D/A of Eagle Rock Energy Partners, L.P. on August 17, 2011 (the “Joint Filing Agreement”), is amended to: (i) add NGP Income Co-Investment Opportunities Fund II, L.P. (“NGP Co-Invest”) and NGP Energy Capital Management, L.L.C. (“NGP ECM”) as parties to the Joint Filing Agreement, whereby NGP Co-Invest and NGP ECM agree to be bound by the terms and conditions of the Joint Filing Agreement and (ii) remove Kenneth A. Hersh as a party to the Joint Filing Agreement, whereby Kenneth A. Hersh will no longer be bound by the terms and conditions of the Joint Filing Agreement.

Dated: September 22, 2014

MONTIERRA MINERALS & PRODUCTION, L.P. By its general partner, Montierra Management LLC
By:	/s/ Joseph A. Mills
Joseph A. Mills
Chief Executive Officer
MONTIERRA MANAGEMENT LLC
By:	/s/ Joseph A. Mills
Joseph A. Mills
Chief Executive Officer
NATURAL GAS PARTNERS VII, L.P. By its general partner, G.F.W. Energy VII, L.P. By its general partner, GFW VII, L.L.C.
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Authorized Member
NATURAL GAS PARTNERS VIII, L.P. By its general partner, G.F.W. Energy VIII, L.P. By its general partner, GFW VIII, L.L.C.
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Authorized Member

NGP INCOME MANAGEMENT L.L.C.
By:	/s/ Tony R. Weber
Tony R. Weber
President
EAGLE ROCK HOLDINGS NGP 7, LLC By its sole member, Natural Gas Partners VII, L.P. By its general partner, G.F.W. Energy VII, L.P. By its general partner, GFW VII, L.L.C.
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Authorized Member
EAGLE ROCK HOLDINGS NGP 8, LLC By its sole member, Natural Gas Partners VIII, L.P. By its general partner, G.F.W. Energy VIII, L.P. By its general partner, GFW VIII, L.L.C.
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Authorized Member
ERH NGP 7 SPV, LLC
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Chief Executive Officer & President

ERH NGP 8 SPV, LLC
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Chief Executive Officer & President
NGP INCOME CO-INVESTMENT OPPORTUNITIES FUND II, L.P. By its general partner, NGP Income Co-Investment II GP, L.L.C.
By:	/s/ Tony R. Weber
Tony R. Weber
President
NGP ENERGY CAPITAL MANAGEMENT, L.L.C.
By:	/s/ Kenneth A. Hersh
Kenneth A. Hersh
Chief Executive Officer
/s/ Kenneth A. Hersh
Kenneth A. Hersh