| 201 | John J. Welsh | | Oil & Gas Operator | Dec 2024 |
| 202 | John L. Copeland | | Oil & Gas Operator | Jun 1982 |
| 203 | John T. Palmer | | Oil & Gas Operator | Jun 1982 |
| 204 | Jones Operating Company | Levelland, TX 79336 | Oil & Gas Operator | Oct 2000 |
| 205 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Dec 2025 |
| 206 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 207 | KCS Resources LLC | Houston, TX 77027 | Oil & Gas Operator | Feb 2017 |
| 208 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 209 | Kelley Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jan 2002 |
| 210 | Kelly H Baxter | Austin, TX 78767 | Oil & Gas Operator | Nov 2006 |
| 211 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Oct 2025 |
| 212 | Key Energy Services, Inc.Altd | | Oil Operator | Dec 2006 |
| 213 | Key Energy Services, LLC | Houston, TX 77042 | Oil Operator | Jan 2025 |
| 214 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Oct 2025 |
| 215 | Knight Casing Pulling Company | | Oil Operator | Jun 1989 |
| 216 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |
| 217 | L P C Energy, Inc. | | Oil & Gas Operator | Mar 1985 |
| 218 | L'Oil Operating & Management Co., Inc. | | Oil & Gas Operator | Nov 2024 |
| 219 | L'Oil Operating And MGMT. Co. | | Oil & Gas Operator | Dec 2008 |
| 220 | L. E. Gillespie | | Oil Operator | Sep 1984 |
| 221 | Lamamco Drilling Company | Skiatook, OK 74070 | Oil & Gas Operator | Oct 2025 |
| 222 | Lamar Hunt | | Oil & Gas Operator | Oct 2003 |
| 223 | Lamar Smith | | Oil Operator | Aug 1991 |
| 224 | Latham Exploration Company Inc | | Oil & Gas Operator | Aug 1992 |
| 225 | Lawson Engineering, Inc. | | Oil & Gas Operator | Dec 1984 |
| 226 | Lear Gas Transmission | | Oil Operator | Aug 1989 |
| 227 | Lear Petroleum Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 228 | Leatherman Creek, Inc. | | Oil Operator | Jul 2001 |
| 229 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 230 | Linn Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 231 | Live Oak Energy, Inc. | | Oil & Gas Operator | Dec 2011 |
| 232 | Lobo Operating, Inc. | Houston, TX 77077 | Oil & Gas Operator | Dec 2024 |
| 233 | Long Oil & Natural Gas Corp. | | Oil & Gas Operator | Feb 1996 |
| 234 | Louisiana Operating Co., Inc. | | Oil & Gas Operator | Aug 1994 |
| 235 | Louisiana-Hunt Petroleum Corp. | | Oil & Gas Operator | Dec 1985 |
| 236 | Lowmar Exploration Co. | | Oil & Gas Operator | Feb 1990 |
| 237 | Lyons Petroleum, Inc. | | Oil & Gas Operator | Oct 1988 |
| 238 | M & B Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Sep 2025 |
| 239 | M. H.Marr | | Oil & Gas Operator | Mar 1998 |
| 240 | M. S. Delone | | Oil Operator | Nov 1990 |
| 241 | Ma-Si, Inc. | | Oil & Gas Operator | May 1998 |
| 242 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 243 | Marathon Oil Company/Fina | | Oil & Gas Operator | Jan 2005 |
| 244 | Marlin And Davis | | Oil Operator | Sep 1987 |
| 245 | Marr Company | | Oil & Gas Operator | Mar 1989 |
| 246 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 247 | Maverick Oil Co. | Richland, TX 76681 | Oil Operator | Dec 2025 |
| 248 | Maverick Producers, Inc. | | Oil Operator | May 2012 |
| 249 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 250 | McKenzie Petroleum Company | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 251 | McKenzie Production Company | Houston, TX 77063 | Oil & Gas Operator | May 1995 |
| 252 | McRae Exploration, Inc. | | Oil & Gas Operator | Mar 1984 |
| 253 | McRae Exploration, Inc. & Epm | | Oil & Gas Operator | Mar 1978 |
| 254 | McRae Exploration, Inc. & Herd | | Oil & Gas Operator | Mar 1984 |
| 255 | McRae Exploration,Inc & Bec | | Oil & Gas Operator | Feb 1984 |
| 256 | McRae Oil Corporation | | Oil & Gas Operator | Mar 1984 |
| 257 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 258 | Midroc Operating Company | | Oil & Gas Operator | Apr 2013 |
| 259 | Minatome Corpora | | Oil & Gas Operator | Sep 1987 |
| 260 | Mineral Ventures, Inc. | | Oil & Gas Operator | Dec 2024 |
| 261 | Minerex Engineering Corp. | | Oil & Gas Operator | Mar 2004 |
| 262 | MJ Energy, LLC Of Arkansas | | Oil Operator | Jan 2025 |
| 263 | Mobil E&P North America Inc. | | Oil & Gas Operator | Jan 1994 |
| 264 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 265 | Monroe Well Ser-New American85 | | Oil Operator | Dec 1988 |
| 266 | Monroe Well Serv-New American | | Oil Operator | Dec 1988 |
| 267 | Monroe Well Service | | Oil & Gas Operator | Apr 1998 |
| 268 | Monroe Well Service-Broadway | | Oil Operator | Dec 1988 |
| 269 | Monroe Well Service-Petrol | | Oil Operator | Sep 1992 |
| 270 | Monroe Well Service-Petrovest | | Oil Operator | Dec 1988 |
| 271 | Monroe Well Service-Shemen | | Oil Operator | Dec 1988 |
| 272 | Monterey Resources LLC | Dallas, TX 75230 | Oil & Gas Operator | Oct 2019 |
| 273 | MRD Operating LLC | | Oil & Gas Operator | Dec 2016 |
| 274 | Mrs. C. M. Roberson | | Oil Operator | Mar 1989 |
| 275 | MRT Exploration Co | | Oil & Gas Operator | Feb 1983 |
| 276 | Murphy Exploration & Prod. Co. | Houston, TX 77094 | Oil & Gas Operator | Jun 2011 |
| 277 | Murphy Oil USA, Inc. | New Orleans, LA 70161 | Oil & Gas Operator | Jan 1993 |
| 278 | Nadel & Gussman | Tulsa, OK 74103 | Oil & Gas Operator | May 2007 |
| 279 | Nadel & Gussman-Jetta Oper. Co. | | Oil & Gas Operator | Mar 2012 |
| 280 | Nadel And Gussman LLC | Tulsa, OK 74119 | Oil & Gas Operator | Dec 2025 |
| 281 | Nadel And Gussman Ruston, LLC | | Oil & Gas Operator | Dec 2024 |
| 282 | Neilco | | Oil & Gas Operator | Nov 2024 |
| 283 | Nelson Energy, Inc. | | Oil & Gas Operator | Nov 2024 |
| 284 | Nelson Oil & Gas, Inc. | | Oil & Gas Operator | Aug 1995 |
| 285 | Nerco Oil & Gas Inc | | Oil & Gas Operator | Dec 1996 |
| 286 | NFR Energy, LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2017 |
| 287 | NGL Processing, LLC | | Oil Operator | Jun 2000 |
| 288 | Nichols Oil & Gas Corporation | Shreveport, LA 71135 | Oil & Gas Operator | Aug 2003 |
| 289 | Noram Field Services Corp. | | Oil Operator | Apr 1999 |
| 290 | Nortex Oil & Gas, Inc. | | Oil Operator | Feb 1994 |
| 291 | O'Brien Operating Company | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2004 |
| 292 | O. B. Mobley | | Oil & Gas Operator | Jul 1989 |
| 293 | Oakland Corporation | | Oil & Gas Operator | Dec 1981 |
| 294 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 295 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Dec 2025 |
| 296 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 297 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 298 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 299 | Palmer Petroleum, Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Jun 2025 |
| 300 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |