X0303 4 2008-11-17 0 0001364541 EAGLE ROCK ENERGY PARTNERS L P EROC 0001377257 Eagle Rock Holdings, L.P. 16701 GREENSPOINT PARK DRIVE, SUITE 200 HOUSTON TX 77060 0 0 1 0 0001398059 Montierra Management LLC 16701 GREENSPOINT PARK DRIVE, SUITE 200 HOUSTON TX 77060 0 0 0 1 GP of MMP 0001378412 Eagle Rock GP, LLC 16701 GREENSPOINT PARK DRIVE, SUITE 200 HOUSTON TX 77060 0 0 0 1 GP of Eagle Rock Holdings 0001398061 Montierra Minerals & Production, L.P. 16701 GREENSPOINT PARK DRIVE, SUITE 200 HOUSTON TX 77060 0 0 0 1 Affiliate of EROC 0001377292 Natural Gas Partners VII, L.P. 125 E. JOHN CARPENTER FWY SUITE 600 IRVING TX 75062 0 0 1 0 0001377291 Natural Gas Partners VIII, L.P. 125 E. JOHN CARPENTER FWY SUITE 600 IRVING TX 75062 0 0 1 0 0001398214 NGP Co-Investment Income Capital Corp. 125 E. JOHN CARPENTER FREEWAY, SUITE 600 IRVING TX 75062 0 0 0 1 Affiliate of EROC 0001398088 NGP 2004 Co-Investment Income, L.P. 125 E. JOHN CARPENTER FREEWAY, SUITE 600 IRVING TX 75062 0 0 0 1 Affiliate of EROC 0001398089 NGP-VII Income Co-Investment Opportunities, LP 125 E. JOHN CARPENTER FREEWAY, SUITE 600 IRVING TX 75062 0 0 0 1 Affiliate of EROC 0001398062 NGP Income Management, L.L.C. 125 E. JOHN CARPENTER FREEWAY, SUITE 600 IRVING TX 75062 0 0 0 1 Affiliate of EROC Common Units representing limited partner interests 2008-11-17 4 P 0 13600 8.067 A 12125120 D Common Units representing limited partner interests 2008-11-18 4 P 0 25000 7.623 A 12150120 D Common Units representing limitd partner interests 2008-11-19 4 P 0 17500 7.401 A 12167620 D Common Units representing limited partner interests 2008-11-19 4 P 0 7500 7.401 A 12175120 D Represents the purchase of 13,600 units by Eagle Rock Holdings, L.P. ("Holdings"), pursuant to and intended to comply with Rule 10b-18 under the Securities Exchange Act of 1934 at per unit prices ranging from $8.22 to $7.83, resulting in a weighted average purchase price per unit of $8.067. Holdings has provided to the issuer and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of units purchased at each price within the range. Represents the purchase of 25,000 units by Holdings, pursuant to and intended to comply with Rule 10b-18 under the Securities Exchange Act of 1934 at per unit prices ranging from $7.88 to $7.35, resulting in a weighted average purchase price per unit of $7.623. Holdings has provided to the issuer and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of units purchased at each price within the range. Represents the purchase of 17,500 units by Eagle Rock Holdings, L.P. ("Holdings"), pursuant to and intended to comply with Rule 10b-18 under the Securities Exchange Act of 1934 at per unit prices ranging from $7.83 to $7.20, resulting in a weighted average purchase price per unit of $7.401. Holdings has provided to the issuer and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of units purchased at each price within the range. Represents the purchase of 7,500 units by Montierra Minerals & Producton, L.P. ("Montierra"), pursuant to and intended to comply with Rule 10b-18 under the Securities Exchange Act of 1934 at per unit prices ranging from $7.83 to $7.20, resulting in a weighted average purchase price per unit of $7.401. Montierra has provided to the issuer and will provide to any security holder of the issuer, or the SEC staff, upon request, information regarding the number of units purchased at each price within the range. Natural Gas Partners VII, L.P. ("NGP VII") and Natural Gas Partners VIII, L.P. collectively own 79.83% of Eagle Rock Holdings, L.P. including LP and GP interests and a 96.169% LP interest in Montierra. NGP VII also owns a 97.561% interest in Montierra Management LLC ("Montierra Management"), which serves as the general partner of Montierra. NGP VII owns 100% of NGP Income Management L.L.C. which serves as the general partner of both NGP-VII Income Co-Investment Opportunities, L.P. ("NGP-VII Income Co-Investment") and NGP 2004 Co-Investment Income, L.P. ("NGP 2004"). NGP-VII Income Co-Investment owns 100% of NGP Co-Investment Income Capital Corp. ("NGP Capital Corp."). NGP VII may be deemed to beneficially own all of the reported securities of NGP 2004 and NGP Capital Corp. Kenneth A. Hersh may be deemed to share dispositive power over the units held by NGP VII, thus, he may also be deemed to be the beneficial owner of these units. This report is filed in connection with the Form 4 filed today by Kenneth A. Hersh. The reporting persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interests therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owner of the reported securities for purposes of Section 16 or for any other purpose. Eagle Rock Holdings, L.P., By its general partner, Eagle Rock GP, LLC, By /s/ Kenneth A. Hersh, Manager 2008-11-19 Eagle Rock GP, LLC, By /s/ Kenneth A. Hersh 2008-11-19 Montierra Minerals & Production, L.P., By its general partner, Montierra Management LLC, By /s/ Joseph A. Mills, Chief Executive Officer 2008-11-19 Montierra Management LLC, By /s/ Joseph A. Mills, Chief Executive Officer 2008-11-19 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, Authorized Member 2008-11-19 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, Authorized Member 2008-11-19 NGP Income Management, L.L.C., By /s/ Tony R. Weber, President 2008-11-19 NGP-VII Income Co-Investment Opportunities, L.P., By /s/ Tony R. Weber, President 2008-11-19 NGP 2004 Co-Investment Income, L.P., By its general partner, NGP Income Management L.L.C., By /s/ Tony R. Weber, President 2008-11-19 NGP Co-Investment Income Capital Corp., By /s/ Tony R. Weber, President 2008-11-19