| 101 | Cornerstone Natural Resources LLC | Denver, CO 80234 | Oil & Gas Operator | Oct 2025 |
| 102 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 103 | Crescent Point Energy Us Corp | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 104 | Crystal Exploration & Production Company | Shreveport, LA 71120 | Oil & Gas Operator | Feb 1995 |
| 105 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 106 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 107 | Dakota Crude, Inc. | | Oil & Gas Operator | Oct 2025 |
| 108 | Dakota Oil Company | Hebbronville, TX 78361 | Oil & Gas Operator | Dec 2025 |
| 109 | Dakota West Pumping, Inc. | | Oil & Gas Operator | Feb 2004 |
| 110 | Dakota-3 E&P Company, LLC | | Oil & Gas Operator | Jan 2012 |
| 111 | David H Arrington Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 112 | Deep Creek Adventures, Co. | | Oil Operator | Dec 2018 |
| 113 | Denali Oil & Gas Management LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 114 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 115 | Depco Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2014 |
| 116 | Depco, Inc. & Texas Pacific Oil Co. | | Oil Operator | Jul 1995 |
| 117 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 118 | Devon Energy Williston, L.L.C | Oklahoma City, OK 73102-8260 | Oil & Gas Operator | Sep 2025 |
| 119 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Dec 2025 |
| 120 | Dome Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 121 | Dominion Oklahoma Texas Expl & Prod Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Aug 2013 |
| 122 | Donald C. Slawson | | Oil Operator | Jun 1985 |
| 123 | Dorchester Exploration, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2001 |
| 124 | Double Aa Oil, L.L.C. | | Oil Operator | Aug 2023 |
| 125 | Drawings, LLC | Albuquerque, NM 87109 | Oil Operator | Aug 2025 |
| 126 | Dry Creek Disposal Company, Inc. | | Oil & Gas Operator | Nov 2021 |
| 127 | Eagle Operating, Inc. | Minot, ND 58701 | Oil & Gas Operator | Oct 2025 |
| 128 | Earl Schwartz Co. | | Oil & Gas Operator | Oct 1989 |
| 129 | Earthstone Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2017 |
| 130 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Sep 2025 |
| 131 | Edward Mike Davis | Las Vegas, NV 89107 | Oil & Gas Operator | Feb 2003 |
| 132 | Edward Mike Davis, L.L.C. | | Oil & Gas Operator | Dec 2006 |
| 133 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Sep 2025 |
| 134 | Elk Oil Company | Overland Park, KS 66212 | Oil & Gas Operator | Sep 2007 |
| 135 | Emerald Oil, Inc | | Oil & Gas Operator | Dec 2016 |
| 136 | Empire North Dakota LLC | Tulsa, OK 74114 | Oil & Gas Operator | Oct 2025 |
| 137 | Encore Energy Partners Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2015 |
| 138 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Sep 2025 |
| 139 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 140 | Enduro Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2018 |
| 141 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Oct 2025 |
| 142 | Energy Operating Company Inc | Lakewood, CO 80235 | Oil & Gas Operator | Dec 2012 |
| 143 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Aug 2025 |
| 144 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 145 | Ensign Operating Co. | Denver, CO 80202 | Oil & Gas Operator | Jan 2004 |
| 146 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 147 | Equinor Energy LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2021 |
| 148 | Evertson Operating Company Inc | Kimball, NE 69145 | Oil & Gas Operator | Nov 2022 |
| 149 | Exeter Exploration Co. | | Oil & Gas Operator | Aug 1985 |
| 150 | Exploration Company, The | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2010 |
| 151 | F & L Petroleum, LLC | | Oil & Gas Operator | Apr 2019 |
| 152 | Farmers Union Central Exchange, Inc. | | Oil & Gas Operator | May 1983 |
| 153 | FH Petroleum Corp. | Billings, MT 59103 | Oil & Gas Operator | Oct 2025 |
| 154 | Fidelity Exploration & Production Company | Denver, CO 80203 | Oil & Gas Operator | Nov 2025 |
| 155 | Filco Incorporated | | Oil & Gas Operator | Oct 2025 |
| 156 | Five States Operating Company LLC | Dallas, TX 75206 | Oil & Gas Operator | Oct 2025 |
| 157 | Flatirons Resources LLC | Westminster, CO 80021 | Oil & Gas Operator | Dec 2022 |
| 158 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 159 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 160 | Formentera Operations LLC | Austin, TX 78701 | Oil & Gas Operator | Dec 2025 |
| 161 | Fortson Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2020 |
| 162 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Dec 2025 |
| 163 | Four Starr Production, LLC | Dallas, TX 75243 | Oil & Gas Operator | Dec 2025 |
| 164 | Fox Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 165 | Fram Operating LLC | | Oil & Gas Operator | Dec 2018 |
| 166 | Fulcrum Energy Operating, LLC | Denver, CO 80206 | Oil & Gas Operator | Dec 2025 |
| 167 | G3 Operating, LLC | | Oil & Gas Operator | May 2013 |
| 168 | Gadeco, LLC | | Oil & Gas Operator | Oct 2025 |
| 169 | Galaxy Oil | | Oil & Gas Operator | Oct 2025 |
| 170 | Galaxy Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 2015 |
| 171 | Gas Producing Enterprises, Inc. | | Oil & Gas Operator | Oct 1985 |
| 172 | Genesis St Operating LLC | Kansas City, MO 64108 | Oil & Gas Operator | Dec 2025 |
| 173 | Geolinear Co. | | Oil & Gas Operator | Jul 1996 |
| 174 | Georesources, Inc. | Williston, ND 58802-1505 | Oil & Gas Operator | Dec 2014 |
| 175 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 176 | GMX Resources, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2014 |
| 177 | Golden Eye Resources LLC | Greenwood VLG, CO 80121 | Oil Operator | Mar 2014 |
| 178 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 179 | Grayson Mill Operating LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 180 | Great American Exploration, Inc. | | Oil Operator | Feb 1979 |
| 181 | Great American Royalties, Inc. | | Oil Operator | Nov 2025 |
| 182 | Great Western Drilling Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 183 | Griffon & Associates, L.L.C. | Pearland, TX 77581 | Oil & Gas Operator | Jul 2008 |
| 184 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 185 | Gypsy Highview Gathering System, Inc. | Cut Bank, MT 59427-0250 | Oil & Gas Operator | Oct 2000 |
| 186 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 187 | H. L. Hunt | | Oil & Gas Operator | Jun 1980 |
| 188 | Hardy Salt Co. | | Oil & Gas Operator | Apr 1986 |
| 189 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 190 | Helis Oil & Gas Company, L.L.C. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2023 |
| 191 | Hess Bakken Investments II, LLC | | Oil & Gas Operator | Oct 2025 |
| 192 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 193 | High Plains Operating, LLC | | Oil Operator | Oct 2025 |
| 194 | Hilliard Oil & Gas, Inc. | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 195 | HNG Oil Company | | Oil & Gas Operator | Jun 1987 |
| 196 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Dec 2025 |
| 197 | Houston Exploration Co, The | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 198 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 199 | HRC Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2017 |
| 200 | Hunt Energy Corporation | | Oil & Gas Operator | Feb 2002 |