| 201 | Eason Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2012 |
| 202 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 203 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 204 | Egan Resources Inc. | Katy, TX 77494 | Oil & Gas Operator | Oct 2016 |
| 205 | Egolf Operating Company | Oklahoma City, OK 73114-7899 | Oil & Gas Operator | Apr 1998 |
| 206 | El Paso Natural Gas Company | El Paso, TX 79978 | Oil & Gas Operator | Apr 2013 |
| 207 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 208 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Apr 2025 |
| 209 | Elk Oil Company | Overland Park, KS 66212 | Oil & Gas Operator | Sep 2007 |
| 210 | Elm Ridge Exploration Company LLC | Bloomfield, NM 87413 | Oil & Gas Operator | Nov 2017 |
| 211 | Elmore Stanley G | Bartlesville, OK 74006-1741 | Oil & Gas Operator | Sep 2023 |
| 212 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | Feb 2024 |
| 213 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 214 | Energy Resources Dev Inc | Bixby, OK 74008-3658 | Oil & Gas Operator | Apr 2025 |
| 215 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 216 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 217 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 218 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 219 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 220 | Excalibur Resources LLC | Houston, TX 77002-5220 | Oil & Gas Operator | Apr 2025 |
| 221 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 222 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Apr 2025 |
| 223 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 224 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | May 2025 |
| 225 | F C D Oil Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 1995 |
| 226 | Fairway Resources Operating III LLC | Houston, TX 77002-2728 | Oil & Gas Operator | Apr 2025 |
| 227 | Faulconer Vernon E Inc | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 228 | Faulkner Corporation | Oklahoma City, OK 73154-9704 | Oil & Gas Operator | Jan 2017 |
| 229 | FBF Energy LLC | Tulsa, OK 74120 | Oil & Gas Operator | May 2025 |
| 230 | FG III LLC | Colleyville, TX 76034-4963 | Oil & Gas Operator | Apr 2018 |
| 231 | Flag-Redfern Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Jul 2002 |
| 232 | Focus Energy, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2019 |
| 233 | Foreman Enterprises, Inc. | Edmond, OK 73003 | Oil & Gas Operator | May 2025 |
| 234 | Forest Oil Permian Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 235 | Fossil Creek Energy Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2025 |
| 236 | Four Seas Exploration LLC | Oklahoma City, OK 73101-1557 | Oil & Gas Operator | Dec 2019 |
| 237 | FP Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2008 |
| 238 | Fuller Petroleum Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 239 | FX Energy Operating, LLC | Canadian, TX 79014 | Oil & Gas Operator | Jul 2025 |
| 240 | G A W Oil Company LLC | Enid, OK 73702-3926 | Oil & Gas Operator | May 2025 |
| 241 | Gala Resources, LTD. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 242 | Gastar Exploration LLC | Tulsa, OK 74136-1921 | Oil & Gas Operator | Apr 2025 |
| 243 | Gene Cook Inc | Woodward, OK 73801 | Oil & Gas Operator | May 2025 |
| 244 | General Atlantic Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 245 | General Minerals Corp | Oklahoma City, OK 73105 | Oil & Gas Operator | Dec 2015 |
| 246 | General Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jun 1993 |
| 247 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 248 | Geodyne Resources Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2010 |
| 249 | Getty Reserve Oil, Inc. | White Plains, NY 10650 | Oil & Gas Operator | Mar 2005 |
| 250 | GLB Exploration, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 251 | Golden Gas Production Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2025 |
| 252 | Gothic Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jul 2015 |
| 253 | Gothic Production Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2016 |
| 254 | GPM Gas Corp | Oklahoma City, OK 73102-5627 | Oil & Gas Operator | Nov 1998 |
| 255 | Graham Oil And Gas, LTD. | Covington, LA 70434-3134 | Oil & Gas Operator | Aug 2013 |
| 256 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 257 | Graham-Michaelis Corporation | Wichita, KS 67201 | Oil & Gas Operator | Dec 2010 |
| 258 | Griffin Resources LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2025 |
| 259 | Guest Petroleum Incorporated | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 260 | Guest R E Oil Producer | Edmond, OK 73083-0805 | Oil & Gas Operator | Mar 2015 |
| 261 | Gulf Exploration, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2025 |
| 262 | H & H Oil Productions | Tulsa, OK 74145 | Oil Operator | Jul 1999 |
| 263 | H & L Operating Company | Amarillo, TX 79114 | Oil & Gas Operator | Feb 2020 |
| 264 | Hadson Petro USA Inc | | Oil & Gas Operator | Nov 2016 |
| 265 | Hadson Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 266 | Halcon Holdings Inc | Ada, OK 74820 | Oil & Gas Operator | Nov 2018 |
| 267 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 268 | Harding & Shelton Inc | Oklahoma City, OK 73104-2410 | Oil & Gas Operator | Apr 2025 |
| 269 | Harding And Shelton Exploration LLC | Oklahoma City, OK 73101-1557 | Oil & Gas Operator | Apr 2025 |
| 270 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 271 | Harris Oil & Gas Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2016 |
| 272 | Harwood Oil & Gas Inc | Greeley, CO 80631-8233 | Oil & Gas Operator | Apr 2025 |
| 273 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 274 | Hazelwood Prod & Exp Co LLC | Oklahoma City, OK 73116-9037 | Oil & Gas Operator | Apr 2025 |
| 275 | HCG Energy Corporation & Subs | | Oil & Gas Operator | Mar 2015 |
| 276 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 277 | Heartland Environmental Services | Watonga, OK 73080 | Oil & Gas Operator | May 1999 |
| 278 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Mar 2025 |
| 279 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Jul 2025 |
| 280 | Highland Minerals, Inc. | Tulsa, OK 74145-7627 | Oil & Gas Operator | Apr 2015 |
| 281 | Hinkle Oil And Gas Inc | Oklahoma City, OK 73112-4275 | Oil & Gas Operator | May 2025 |
| 282 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | May 2025 |
| 283 | Hondo Oil & Gas Company | Roswell, NM 88202 | Oil & Gas Operator | Aug 2006 |
| 284 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Oct 2024 |
| 285 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 286 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 287 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Jul 2025 |
| 288 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 289 | Huitt Joe A | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 290 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 291 | Hunt Engineering Inc | Norman, OK 73069-4093 | Oil & Gas Operator | Feb 2019 |
| 292 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 293 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jul 2025 |
| 294 | Hunton Oil & Gas Corporation | Oklahoma City, OK 73154-0191 | Oil & Gas Operator | May 2019 |
| 295 | Indian Oil Company | Gainesville, TX 76241 | Oil & Gas Operator | Jul 2025 |
| 296 | Internorth Inc | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2014 |
| 297 | Iochem Corporation | Oklahoma City, OK 73118-7483 | Oil & Gas Operator | Apr 2025 |
| 298 | Irex Corporation | Englewood, CO 80111 | Oil & Gas Operator | May 2000 |
| 299 | J & R Transports Inc | Woodward, OK 73802 | Oil & Gas Operator | Dec 2006 |
| 300 | J-Brex Company | Amarillo, TX 79101 | Oil & Gas Operator | Jul 2025 |