| 101 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 102 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 103 | Cox & Perkins Exploration, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 104 | Crawford Energy Operating Co | Houston, TX 77056 | Oil & Gas Operator | Aug 2008 |
| 105 | Crawford Hughes Operating Co. | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 106 | Creative Oil & Gas Operating,LLC | Giddings, TX 78942 | Oil & Gas Operator | May 2024 |
| 107 | Crescent Exploration Company | Austin, TX 78767 | Oil & Gas Operator | Aug 1995 |
| 108 | Crimson Energy Company, LC | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2004 |
| 109 | CRM Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Oct 2025 |
| 110 | Cumming Company, Inc. The | Fort Worth, TX 76116 | Oil & Gas Operator | Oct 2025 |
| 111 | Cyber Enviro-Tech Inc | San Tan Valley, AZ 85144 | Oil & Gas Operator | Oct 2025 |
| 112 | Cymri, L.L.C. | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 113 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 114 | Dallas Petroleum Group, LLC | Dallas, TX 75379 | Oil & Gas Operator | Oct 2025 |
| 115 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 116 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 117 | Delaware Ecco Petroleum Inc. | Rockwall, TX 75087 | Oil & Gas Operator | Jul 2001 |
| 118 | Diamond Oil And Gas, Inc. | Kalamazoo, MI 49001 | Oil & Gas Operator | Oct 2025 |
| 119 | Dixie Drilling Company, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Nov 2011 |
| 120 | DKM Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Sep 2011 |
| 121 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 122 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 123 | Domino Prod Services Inc | Bellville, TX 77418 | Oil & Gas Operator | Feb 2004 |
| 124 | Douglas Petroleum Inc. | Spring, TX 77379 | Oil & Gas Operator | Nov 2010 |
| 125 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 126 | Durst Oil Company | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Sep 2000 |
| 127 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |
| 128 | Dyson Energy Operating, LLC | Bryan, TX 77802 | Oil & Gas Operator | Jun 2018 |
| 129 | E P C Oil & Gas, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Oct 2025 |
| 130 | Eagle Valley Development LLC | Austin, TX 78738 | Oil & Gas Operator | Oct 2023 |
| 131 | Eclipse Services, Inc. * | La Grange, TX 78945 | Oil & Gas Operator | Jul 2003 |
| 132 | Edco Energy, Inc. | Austin, TX 78738 | Oil & Gas Operator | May 2003 |
| 133 | Edwards, Gus Co. | Abilene, TX 79603 | Oil & Gas Operator | Jun 2004 |
| 134 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 135 | Energy Resource Management, Inc. | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 136 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 137 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 138 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 139 | Ernest Operating Company | Rockdale, TX 76567 | Oil & Gas Operator | Oct 2025 |
| 140 | Esenjay Petroleum Corp. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jul 1998 |
| 141 | Et Gathering & Processing LLC | Dallas, TX 75225 | Oil Operator | Dec 2024 |
| 142 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 143 | Etoco Incorporated | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 144 | Etx Energy, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2022 |
| 145 | Evolution Operating Co., Inc. | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 146 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 147 | Exploration Techniques Inc. | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 148 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Oct 2025 |
| 149 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 150 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 151 | F & J Petroleum Company | Milano, TX 76556 | Oil Operator | Oct 2025 |
| 152 | F.I.G. Energy, LLC | Livingston, TX 77399 | Oil & Gas Operator | Oct 2025 |
| 153 | FDL Operating, LLC | Judson, TX 75660 | Oil & Gas Operator | Oct 2025 |
| 154 | Fenn, Bill Inc. | Giddings, TX 78942 | Oil & Gas Operator | Mar 2008 |
| 155 | Ferguson-Burns Leasing Co. | Rockdale, TX 76567 | Oil & Gas Operator | Oct 2007 |
| 156 | Finaly Resources LLC | Sunset Beach, CA 90742 | Oil & Gas Operator | Oct 2025 |
| 157 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 158 | Flairtex Resources, Inc. | Houston, TX 77040 | Oil & Gas Operator | Oct 1998 |
| 159 | Frostwood Energy, LLC | Houston, TX 77219 | Oil & Gas Operator | Oct 2025 |
| 160 | Future Petroleum Company LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2013 |
| 161 | Future Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 1999 |
| 162 | G E Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2020 |
| 163 | Gaither Petroleum Corporation | Katy, TX 77493 | Oil & Gas Operator | Oct 2025 |
| 164 | Galloway Energy Co. | Tomball, TX 77377 | Oil & Gas Operator | Oct 2025 |
| 165 | Galloway Lone Star, L.L.C. | Tomball, TX 77377 | Oil & Gas Operator | Oct 2025 |
| 166 | Garrison LTD. | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2025 |
| 167 | Gei Management Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Sep 1993 |
| 168 | Gemini Exploration Company | Dallas, TX 75219 | Oil & Gas Operator | Mar 1997 |
| 169 | Genie Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 170 | Geosouthern Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 171 | Ginco Operating Co. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 172 | Ginger Petroleum Company, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Oct 2025 |
| 173 | Glenco Oil & Gas Company | Seguin, TX 78155 | Oil & Gas Operator | Dec 1994 |
| 174 | Goldrus Producing Company | Houston, TX 77064 | Oil & Gas Operator | Aug 2009 |
| 175 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 176 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 177 | Gsi Oil & Gas, Inc. | Bryan, TX 77806 | Oil & Gas Operator | Oct 2025 |
| 178 | Guest Petroleum Incorporated | Edmond, OK 73013 | Oil & Gas Operator | Jul 2025 |
| 179 | Gulf Central Petroleum Corp. | Dallas, TX 75252 | Oil & Gas Operator | Oct 2025 |
| 180 | GWM Operating Company, LLC | Sugar Land, TX 77479 | Oil & Gas Operator | Oct 2025 |
| 181 | H. Bryan Poff, LLC | Cedar Park, TX 78613 | Oil & Gas Operator | Oct 2018 |
| 182 | H.K.E. | Stafford, TX 77497 | Oil & Gas Operator | Oct 2025 |
| 183 | Halcon Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 184 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 185 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 186 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 187 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 188 | Harmony Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Oct 2025 |
| 189 | Hawkwood Energy Operating, LLC | Houston, TX 77224 | Oil & Gas Operator | Apr 2022 |
| 190 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 191 | Hawthorn Energy Partners, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Oct 2025 |
| 192 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 193 | Heartland Resources, Inc. | Temple, TX 76501 | Oil & Gas Operator | Mar 2008 |
| 194 | Henry, John Petroleum | Dallas, TX 75225 | Oil & Gas Operator | Dec 2001 |
| 195 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Oct 2025 |
| 196 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 197 | Holifield Oil Company | Giddings, TX 78942 | Oil & Gas Operator | Mar 2009 |
| 198 | Holley Oil Company, LLC | Chappell Hill, TX 77426 | Oil & Gas Operator | Oct 2025 |
| 199 | Hollub Production Company | Seguin, TX 78156 | Oil & Gas Operator | Jul 2000 |
| 200 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Oct 2025 |