| 101 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 102 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 103 | Energen Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2021 |
| 104 | Energy 2000, Inc. | Reno, NV 89501 | Oil & Gas Operator | Oct 2025 |
| 105 | Energy Transfer Crude Marketing LLC | Dallas, TX 75225 | Oil Operator | May 2025 |
| 106 | Enerquest Oil & Gas LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 107 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 108 | Ensight Resources, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2001 |
| 109 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 110 | Estate Oil & Gas Corp. | Dallas, TX 75206 | Oil & Gas Operator | Oct 2011 |
| 111 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 112 | Exco Partners Operating PTSHP LP | Dallas, TX 75251 | Oil & Gas Operator | Jan 2009 |
| 113 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 114 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 115 | Faulconer Energy, LLC | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 116 | Finley Resources Inc | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 117 | Floyd Oil Co | Houston, TX 77002 | Oil & Gas Operator | Nov 1999 |
| 118 | Floyd Operating Company | Houston, TX 77002 | Oil & Gas Operator | Jul 2004 |
| 119 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 120 | Forrester Oil & Gas Co. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 121 | Fort Worth Natural Gas, Inc. | Dallas, TX 75254 | Oil & Gas Operator | Oct 2025 |
| 122 | Forte Energy Corporation | Dallas, TX 75205 | Oil & Gas Operator | Dec 2010 |
| 123 | Fortune Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 124 | Four Square Production, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Aug 2004 |
| 125 | Frisco Petroleum Management, LLC | Frisco, TX 75034 | Oil & Gas Operator | Sep 2021 |
| 126 | Genecov Group, Inc. The | Tyler, TX 75713 | Oil & Gas Operator | Dec 2002 |
| 127 | Geo-Vest Of Texas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2008 |
| 128 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 129 | Glade Operating Co. | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 130 | Glade Production | Gladewater, TX 75647 | Oil & Gas Operator | Nov 2008 |
| 131 | Gladewater Production Co., Inc. | Gladewater, TX 75647 | Oil & Gas Operator | Nov 1998 |
| 132 | Goldston Oil Corporation | Houston, TX 77257 | Oil & Gas Operator | Oct 2025 |
| 133 | Goodrich Petroleum Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2022 |
| 134 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 135 | Graward Operating, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Oct 2025 |
| 136 | Graystone Energy Corporation | Judson, TX 75660 | Oil & Gas Operator | Oct 2025 |
| 137 | Gregg Operating, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 138 | Hall Energy Company LLC | Oklahoma City, OK 73120-5020 | Oil & Gas Operator | Jul 2022 |
| 139 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 140 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 141 | Harman Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2007 |
| 142 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 143 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 144 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jun 2025 |
| 145 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 146 | Hinton Production Company | MT Pleasant, TX 75455 | Oil & Gas Operator | Aug 1995 |
| 147 | Hopkins, T. M. Operating Co. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 148 | Howell Oil & Gas, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Oct 2019 |
| 149 | Hugus Investment Company, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 150 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 151 | Huntington Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2006 |
| 152 | Hydrogeo, L.L.C. | Houston, TX 77074 | Oil & Gas Operator | Oct 2025 |
| 153 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 154 | Ironhorse Operations, LLC | Kilgore, TX 75663 | Oil Operator | Oct 2025 |
| 155 | Jil Oil Corp. | San Antonio, TX 78279 | Oil & Gas Operator | Oct 2025 |
| 156 | John P. Bogdanich Operating, LLC | Kilgore, TX 75663 | Oil Operator | Oct 2025 |
| 157 | Jurassic Exploration, Inc. | Longview, TX 75601 | Oil & Gas Operator | Oct 2025 |
| 158 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 159 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 160 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 161 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jun 2025 |
| 162 | Killingsworth, Lee Operator | Longview, TX 75601 | Oil & Gas Operator | Jan 1999 |
| 163 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2025 |
| 164 | Krog Partners, LLC | Kilgore, TX 75663 | Oil Operator | Oct 2025 |
| 165 | L & R Petroleum | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 166 | Lace Operating | Fort Worth, TX 76114 | Oil & Gas Operator | Jun 1997 |
| 167 | Lacy, R., Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2002 |
| 168 | Laddex, LTD. | Amarillo, TX 79102 | Oil & Gas Operator | Feb 2025 |
| 169 | Layline Energy I LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2019 |
| 170 | Lehnertz-Faulkner, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Feb 2023 |
| 171 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 172 | Linder, John G. Jr. | Gladewater, TX 75647 | Oil & Gas Operator | Apr 2005 |
| 173 | Linder, John Operating Co., LLC | Gladewater, TX 75647 | Oil & Gas Operator | Oct 2025 |
| 174 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 175 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 176 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 177 | Long Trusts, The | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 178 | Longview Production, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2002 |
| 179 | M A S Operators | Kilgore, TX 75663 | Oil & Gas Operator | Jul 1999 |
| 180 | M-C Production & Drilling Co,Inc | Longview, TX 75608 | Oil & Gas Operator | Oct 2025 |
| 181 | Manziel Management Corporation | Tyler, TX 75711 | Oil Operator | Feb 2014 |
| 182 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 183 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 184 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 185 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 186 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Oct 2025 |
| 187 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 188 | McBee Operating Company, L.L.C. | Dallas, TX 75209 | Oil & Gas Operator | Oct 2025 |
| 189 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 190 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 191 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 192 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 193 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 194 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 195 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 196 | Miken Oil, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 197 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 198 | Mustang Drilling, Inc. | Henderson, TX 75653 | Oil & Gas Operator | Aug 2024 |
| 199 | Mustang Energy Inc. | Porter, TX 77365 | Oil & Gas Operator | Mar 2008 |
| 200 | Mustang Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2006 |