| 201 | Kansas Oil & Gas Corporation | Woodland HLS, CA 91367 | Oil & Gas Operator | Feb 2001 |
| 202 | Karbuhn Oil Company | Tomball, TX 77375 | Oil & Gas Operator | Dec 2025 |
| 203 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 204 | Kelt Oil & Gas, Inc. | Torrance, CA 90503 | Oil & Gas Operator | Dec 2003 |
| 205 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Oct 2025 |
| 206 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 207 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 208 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 209 | Kingwood Exploration LLC | Shreveport, LA 71105 | Oil & Gas Operator | Dec 2025 |
| 210 | Kody Petroleum Co., Inc. | Daisetta, TX 77533 | Oil & Gas Operator | Dec 2025 |
| 211 | Kriti Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2012 |
| 212 | Lacy, F. B. Inc. | Houston, TX 77055 | Oil & Gas Operator | Sep 1997 |
| 213 | Lake Ronel Oil Company | Tyler, TX 75710 | Oil & Gas Operator | Jul 2017 |
| 214 | Legend Natural Gas III, LP | Houston, TX 77094 | Oil & Gas Operator | Feb 2015 |
| 215 | Legend Natural Gas, LP | Houston, TX 77084 | Oil & Gas Operator | Aug 2004 |
| 216 | Leggett Oil Company | Dallas, TX 75379 | Oil & Gas Operator | Oct 1999 |
| 217 | LGDC Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 218 | Linan Oil & Gas, Inc. | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 219 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 220 | Linder Oil Company,A Partnership | Shreveport, LA 71136 | Oil & Gas Operator | Dec 2025 |
| 221 | Live Oak Op & Production, L.L.C. | Austin, TX 78759 | Oil & Gas Operator | Nov 2011 |
| 222 | Llog Exploration Texas, L.P. | Covington, LA 70433 | Oil & Gas Operator | Dec 2025 |
| 223 | Llox, L.L.C. | Covington, LA 70433 | Oil & Gas Operator | Dec 2025 |
| 224 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 225 | Lucky Lad Energy, LLC | Magnolia, TX 77353 | Oil & Gas Operator | Dec 2025 |
| 226 | M & R Exploration Company | Houston, TX 77074 | Oil & Gas Operator | Aug 2003 |
| 227 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 228 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2025 |
| 229 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 230 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 231 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Sep 2025 |
| 232 | Marmaton Oil Company | Houston, TX 77002 | Oil & Gas Operator | Jul 1998 |
| 233 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 234 | Mascot Oil Company | Schulenburg, TX 78956 | Oil & Gas Operator | Dec 2025 |
| 235 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Oct 2025 |
| 236 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 237 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 238 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 239 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 240 | Metano Energy, LP | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2008 |
| 241 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 242 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 243 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 244 | Milestone Operating, Inc. | Montgomery, TX 77316 | Oil & Gas Operator | Dec 2025 |
| 245 | Minyak Producing Company, Inc. | Sabine Pass, TX 77655 | Oil & Gas Operator | Dec 2025 |
| 246 | Miocene Oil & Gas, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Jul 1998 |
| 247 | Miocene Oil & Gas, LTD. | Englewood, CO 80110 | Oil & Gas Operator | Dec 2025 |
| 248 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 249 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 250 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 251 | Nance Engineering Inc. | Houston, TX 77058 | Oil & Gas Operator | Mar 2002 |
| 252 | Neumin Production Company | Point Comfort, TX 77978 | Oil & Gas Operator | Dec 2025 |
| 253 | New Century Exploration, Inc. | Spring, TX 77379 | Oil & Gas Operator | Dec 2025 |
| 254 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 255 | Newpark Environmental SVCS LLC | Lafayette, LA 70506 | Oil Operator | Jul 2014 |
| 256 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 257 | Nolte, Mike E., Inc. | Longview, TX 75606 | Oil & Gas Operator | Feb 2006 |
| 258 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 259 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 260 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | Dec 2025 |
| 261 | Oilex Int'L Investments, Inc. | Luling, TX 78648 | Oil & Gas Operator | Dec 2025 |
| 262 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 263 | Oklatex Energy, Inc. | Beaumont, TX 77702 | Oil Operator | Dec 2025 |
| 264 | Oleum Exploration, LLC | Brodheadsvill, PA 18322 | Oil & Gas Operator | Mar 2023 |
| 265 | Olipdp II, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Dec 2025 |
| 266 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Dec 2025 |
| 267 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 268 | Osborn,W.B. Oil & Gas Operations | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2025 |
| 269 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2025 |
| 270 | Ows Energy, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Dec 2025 |
| 271 | Panaco Production Co | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 272 | Panaco, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2025 |
| 273 | Papco, Inc. | Warren, PA 16365 | Oil & Gas Operator | Dec 2025 |
| 274 | Par Minerals Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 275 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 276 | Parker & Parsley Producing LP | Midland, TX 79702 | Oil & Gas Operator | Oct 1997 |
| 277 | Patrick Pet. Corp. Of Michigan | Houston, TX 77227 | Oil & Gas Operator | Aug 1995 |
| 278 | Patriot Operating Company, Inc. | Houston, TX 77008 | Oil & Gas Operator | Sep 2003 |
| 279 | Penn VIrginia Oil & Gas Corp | Houston, TX 77024 | Oil & Gas Operator | Dec 2023 |
| 280 | Penn VIrginia Oil & Gas, L.P. | Houston, TX 77084 | Oil & Gas Operator | Nov 2022 |
| 281 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 282 | Permian Natural Resources | Pflugerville, TX 78660 | Oil & Gas Operator | Dec 2025 |
| 283 | Petro Vest, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 2014 |
| 284 | Petrocorp Incorporated,A TX.Corp | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2005 |
| 285 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Jun 2025 |
| 286 | Petrogas Energy Services, LLC | Dallas, TX 75214 | Oil Operator | Dec 2025 |
| 287 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 288 | Petroleum Capital, L.C. | Dallas, TX 75367 | Oil & Gas Operator | Dec 2025 |
| 289 | Petrotex Engineering Company | Cypress, TX 77429 | Oil & Gas Operator | Dec 2025 |
| 290 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 291 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 292 | Phoenix Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2022 |
| 293 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 294 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 295 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 296 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 297 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 298 | Poynor Corporation | Beaumont, TX 77706 | Oil & Gas Operator | Dec 2025 |
| 299 | Preferred Pipeline Corp. | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 300 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2025 |