| 201 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 202 | Dunne Equities Operating, Inc. | Houston, TX 77057 | Oil & Gas Operator | Aug 2022 |
| 203 | E M V Company | | Oil Operator | Oct 2003 |
| 204 | Eagle Operating Inc | Minot, ND 58701 | Oil & Gas Operator | Jan 2025 |
| 205 | Earthstone Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2017 |
| 206 | East Cheyenne Gas Storage LLC | | Oil Operator | Jan 2025 |
| 207 | East Resources Management LLC | | Oil Operator | Oct 2010 |
| 208 | Eastco Operating LLC | | Oil & Gas Operator | Oct 2024 |
| 209 | Eddy Oil Company | | Oil & Gas Operator | May 2013 |
| 210 | Eddy* Harold E & Florence L | | Oil Operator | Jun 2010 |
| 211 | Edge Energy II LLC | Golden, CO 80401 | Oil & Gas Operator | Jan 2025 |
| 212 | Edge Energy LLC | | Oil & Gas Operator | Jan 2025 |
| 213 | Edwards Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 214 | Ee3 LLC | | Oil & Gas Operator | Nov 2015 |
| 215 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 216 | El Paso Energy Raton LLC | | Gas Operator | Sep 2008 |
| 217 | Elk Exploration Inc | | Oil & Gas Operator | Jul 2001 |
| 218 | Ellora LLC | Boulder, CO 80308 | Oil & Gas Operator | Feb 2010 |
| 219 | Elm Ridge Exploration Company LLC | Bloomfield, NM 87413 | Oil & Gas Operator | Nov 2017 |
| 220 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | Feb 2024 |
| 221 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 222 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 223 | Endeavour Operating Corp | Denver, CO 80202-2000 | Oil & Gas Operator | Sep 2015 |
| 224 | Enduring Resources, LLC | Greenwood VLG, CO 80111 | Oil & Gas Operator | Jan 2025 |
| 225 | Energen Resources Corporation | Midland, TX 79701 | Oil & Gas Operator | Jan 2021 |
| 226 | Energy Alliance Company Inc | | Oil & Gas Operator | Jan 2018 |
| 227 | Energy Investments Inc | | Oil & Gas Operator | Feb 2025 |
| 228 | Energy Oil And Gas Inc | | Oil & Gas Operator | Dec 2010 |
| 229 | Energy Operations Colorado LP | | Oil & Gas Operator | Nov 2009 |
| 230 | Energy Operatng Company Inc | | Oil & Gas Operator | Jan 2000 |
| 231 | Energy Search Company Inc | Aurora, CO 80011 | Oil & Gas Operator | Jun 2021 |
| 232 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Nov 2024 |
| 233 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Jan 2025 |
| 234 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 235 | Enervest San Juan Operating | | Gas Operator | Jul 2001 |
| 236 | Enprop Inc | | Oil & Gas Operator | Feb 2013 |
| 237 | Entek GRB LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 238 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 239 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | May 2022 |
| 240 | EP Energy Management LLC | | Oil & Gas Operator | Jun 2006 |
| 241 | Epic Energy LLC | Aztec, NM 87410 | Oil & Gas Operator | Jan 2025 |
| 242 | Equity Oil Company | Salt Lake City, UT 84110-095 | Oil & Gas Operator | Aug 2004 |
| 243 | Erg Resources LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2015 |
| 244 | Evergreen Natural Resources LLC | | Gas Operator | Jan 2025 |
| 245 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 246 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Dec 2024 |
| 247 | Extraction Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2025 |
| 248 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 249 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Dec 2024 |
| 250 | Fahey Oil & Gas | | Oil & Gas Operator | Jul 2021 |
| 251 | Fancher Oil LLC | Greenwood, CO 80111 | Oil & Gas Operator | Nov 2006 |
| 252 | Faulconer Inc* Vernon E | | Gas Operator | Dec 2018 |
| 253 | Fees Jr And Son Oil & Gas* Walter S | | Oil & Gas Operator | Jan 2025 |
| 254 | Fidelity Exploration & Production Company | Denver, CO 80203 | Oil & Gas Operator | Feb 2025 |
| 255 | Fifth Creek Energy Operating Company LLC | | Oil & Gas Operator | Mar 2018 |
| 256 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 257 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 258 | Forestar Group Inc | | Oil & Gas Operator | Sep 2015 |
| 259 | Fortitude Exploration Co | | Oil & Gas Operator | Sep 2024 |
| 260 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Mar 2025 |
| 261 | Fountainhead Resources LTD | | Oil & Gas Operator | Aug 2016 |
| 262 | Four Corners Energy, LLC | Gulf Breeze, FL 32563 | Oil & Gas Operator | Mar 2025 |
| 263 | Four Star Oil & Gas Company | Houston, TX 77252 | Oil & Gas Operator | Nov 2024 |
| 264 | Fram Operating LLC | | Oil & Gas Operator | Dec 2018 |
| 265 | Francis Energy Inc | | Oil & Gas Operator | May 2000 |
| 266 | Fritz & Digman Inc | | Oil Operator | Jan 2025 |
| 267 | Fritzler Resources Inc | Fort Morgan, CO 80701 | Oil & Gas Operator | Dec 2024 |
| 268 | Fulcrum Energy Operating, LLC | Denver, CO 80206 | Oil & Gas Operator | Mar 2025 |
| 269 | Fundare Resources Operating Company LLC | | Oil & Gas Operator | Jan 2025 |
| 270 | Gadeco LLC | | Oil & Gas Operator | Jan 2025 |
| 271 | Genesis Gas & Oil Colorado LLC | | Oil & Gas Operator | Dec 2023 |
| 272 | Genesis Gas & Oil LLC | Kansas City, MO 64108 | Oil & Gas Operator | Aug 2011 |
| 273 | Geomet Operating Co., Inc. | | Gas Operator | Dec 2013 |
| 274 | Geotech Production Inc | Centennial, CO 80016 | Oil & Gas Operator | Jun 2020 |
| 275 | Germany Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Oct 2002 |
| 276 | Gibson J W | | Oil & Gas Operator | Sep 1999 |
| 277 | Gilbert-Stewart Operating LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2024 |
| 278 | Gils Hot Oil Service | | Oil & Gas Operator | Jun 2022 |
| 279 | GMT Exploration Company LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2025 |
| 280 | Goodwin Energy Management LLC | | Oil & Gas Operator | Dec 2022 |
| 281 | Gordon Engineering Inc | | Gas Operator | Dec 2024 |
| 282 | Gosney & Sons Inc | | Gas Operator | Jun 2019 |
| 283 | Gould & Associates* Joseph B | | Gas Operator | Sep 2002 |
| 284 | Grand Mesa Operating Co | Wichita, KS 67206 | Oil & Gas Operator | Feb 2025 |
| 285 | Grand Valley Resources Inc | Seville, OH 44273 | Oil & Gas Operator | Jul 2024 |
| 286 | Grayhorse Operating Inc | Tulsa, OK 74103-4439 | Oil & Gas Operator | Dec 2024 |
| 287 | Great Northern Gas Company | Denver, CO 80293-0602 | Oil & Gas Operator | Jul 2017 |
| 288 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 289 | Great Western Operating Company LLC | | Oil & Gas Operator | Aug 2022 |
| 290 | Griffin Management LLC | | Oil & Gas Operator | Feb 2010 |
| 291 | Grizzly Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Jan 2025 |
| 292 | GRMR Oil And Gas LLC | Broomfield, CO 80021 | Oil & Gas Operator | Feb 2025 |
| 293 | Grynberg* Jack Dba Grynberg Petroleum Co | | Oil & Gas Operator | Jan 2023 |
| 294 | Gulfport Energy Corporation | Oklahoma City, OK 73134-5003 | Oil & Gas Operator | Dec 2024 |
| 295 | Gunnison Energy Corporation | | Oil & Gas Operator | Jun 2014 |
| 296 | Gunnison Energy LLC | | Oil & Gas Operator | Jan 2025 |
| 297 | H & M Petroleum Corporation | Lincoln, NE 68516 | Oil & Gas Operator | Jan 2025 |
| 298 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 299 | Halde Oil Inc | | Oil & Gas Operator | Jan 2025 |
| 300 | Haley/Hughes Operations | | Oil Operator | Apr 2001 |