| 201 | Geodominion Petroleum | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2012 |
| 202 | Gierhart Exploration, Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 1994 |
| 203 | Gillring Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 1994 |
| 204 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 205 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 206 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 207 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 208 | Green Exploration Company | Austin, TX 78711 | Oil & Gas Operator | Mar 2025 |
| 209 | Greenbriar Energy Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2004 |
| 210 | Grover-McKinney Oil Company | Midland, TX 79702 | Oil & Gas Operator | Aug 2003 |
| 211 | Gulfmark Energy Inc | Houston, TX 77027 | Gas Operator | Apr 2023 |
| 212 | H & D Operating Company | Refugio, TX 78377 | Oil & Gas Operator | May 2015 |
| 213 | H R E Rental Company | Premont, TX 78375 | Oil & Gas Operator | Sep 2015 |
| 214 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 215 | Hankey Oil Company | Houston, TX 77027 | Oil & Gas Operator | Feb 2010 |
| 216 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Mar 2025 |
| 217 | Harris Energy Services, LLC | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 218 | Harvey Brothers Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Jul 2004 |
| 219 | Harvey, Mike W. Oil & Gas | Corpus Chrsti, TX 78408 | Oil & Gas Operator | Aug 2003 |
| 220 | Hawn Brothers | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2003 |
| 221 | Hawn Brothers Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jan 2003 |
| 222 | Hawthorne Oil And Gas Corp. | Houston, TX 77227 | Oil & Gas Operator | Sep 1993 |
| 223 | Hays, T.G. Petroleum Expl., Inc. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Dec 1994 |
| 224 | Headington Energy Partners, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 225 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 226 | Headington Oil Company LLC | Dallas, TX 75204 | Oil & Gas Operator | Apr 2016 |
| 227 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 228 | Headline Resources, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Aug 1997 |
| 229 | Hedrick Production Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Mar 2025 |
| 230 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Mar 2025 |
| 231 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 232 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Mar 2025 |
| 233 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 234 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | Mar 2025 |
| 235 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 236 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Mar 2025 |
| 237 | Hugoton Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 238 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 239 | Hunter & Hedrick Production, Inc | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 1995 |
| 240 | Hunter Petroleum Inc. | Alice, TX 78333 | Oil & Gas Operator | May 2014 |
| 241 | Huntington Energy LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2025 |
| 242 | Hurd Enterprises, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2025 |
| 243 | Hydrocarbon Operating, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 244 | Hyquest Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Mar 2015 |
| 245 | Ibc Petroleum, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Mar 2025 |
| 246 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 247 | Infinity Hydrocarbons LLC | Houston, TX 77079 | Oil & Gas Operator | Aug 2022 |
| 248 | Inland Ocean, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Mar 2025 |
| 249 | Intercoastal Energy, Inc. | Houston, TX 77055 | Oil & Gas Operator | Aug 2003 |
| 250 | J G Oil & Gas | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 251 | J Posey Operating LLC | Dayton, TX 77535 | Oil & Gas Operator | Mar 2025 |
| 252 | Jay-Dee Operating Company | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Aug 2000 |
| 253 | Jennings Exploration Company | Beeville, TX 78102 | Oil & Gas Operator | Feb 2024 |
| 254 | JL Resources, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2025 |
| 255 | JMK Petroleum Corp. | Dallas, TX 75251 | Oil & Gas Operator | Jun 2006 |
| 256 | Johnson Resources, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Oct 2011 |
| 257 | Josey Oil Company | Houston, TX 77019 | Oil & Gas Operator | Jul 2006 |
| 258 | Joy Resources, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2025 |
| 259 | JPW Energy, L.L.C. | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2025 |
| 260 | Jubilee Resources, LTD. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Mar 2025 |
| 261 | Jurassic Exploration, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2025 |
| 262 | Kaler Energy Corp. | Boerne, TX 78006 | Oil & Gas Operator | Mar 2025 |
| 263 | Kamlok Oil & Gas, Inc. | Houston, TX 77240 | Oil & Gas Operator | Jun 1996 |
| 264 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Dec 2024 |
| 265 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 266 | Kebo Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 267 | Keen Operating Company, Inc. | Austin, TX 78705 | Oil & Gas Operator | Aug 2001 |
| 268 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Jan 2025 |
| 269 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Mar 2025 |
| 270 | Kinder Morgan Tejas Pipeline LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 271 | Knox Industries, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Mar 2025 |
| 272 | Koch Midstream Services Company | Wichita, KS 67201 | Oil & Gas Operator | Oct 2000 |
| 273 | Kovar Operating, LLC | Victoria, TX 77901 | Oil & Gas Operator | Sep 2021 |
| 274 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |
| 275 | KRC Operating, LLC | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Mar 2025 |
| 276 | Kriken Oil & Gas | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Jul 2005 |
| 277 | L & F Drilling Co., Inc. (1) | Corpus Chrsti, TX 78479 | Oil & Gas Operator | Mar 2025 |
| 278 | L.T.D. Explorations Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2025 |
| 279 | Lamar Oil & Gas, Inc. | Rockport, TX 78381 | Oil & Gas Operator | Mar 2025 |
| 280 | Lamay Corporation | Rosenberg, TX 77471 | Oil & Gas Operator | Mar 2025 |
| 281 | Langham Petroleum Expl. Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 2009 |
| 282 | Lawbar Petroleum, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Aug 2003 |
| 283 | Lee Brothers Oil Co. | Houston, TX 77056 | Oil & Gas Operator | Mar 2008 |
| 284 | Legacy Oil & Gas, Inc. | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 285 | Legend Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | May 2010 |
| 286 | Limestone Oil & Gas Co. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jul 2002 |
| 287 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 288 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 289 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 290 | Little, Lou Operating Co., Inc. | Portland, TX 78374 | Oil & Gas Operator | Sep 2014 |
| 291 | Live Oak/Operations, Inc. | Houston, TX 77019 | Gas Operator | Jul 2011 |
| 292 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 293 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 294 | LR Energy, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Nov 2024 |
| 295 | Lundberg Oil Co. | Dallas, TX 75360 | Oil & Gas Operator | Jan 2003 |
| 296 | Lundberg Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Oct 2002 |
| 297 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 298 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 299 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2025 |
| 300 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |