| 301 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 302 | Keystone Operating Co. | Round Rock, TX 78681 | Oil & Gas Operator | Feb 2026 |
| 303 | Killion Well Service Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2014 |
| 304 | Kimble Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2006 |
| 305 | King Energy Resources | Kerrville, TX 78029 | Oil & Gas Operator | Feb 2026 |
| 306 | King Oil & Gas Co. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 307 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Feb 2026 |
| 308 | Klingberg, Roger | Cross Plains, TX 76443 | Oil & Gas Operator | Jan 2017 |
| 309 | Ko Operating | Merkel, TX 79536 | Oil & Gas Operator | Feb 2026 |
| 310 | Kokomo Energy, Inc. | Gorman, TX 76454 | Oil & Gas Operator | Feb 2026 |
| 311 | Kornye-Tillman Company | Cleburne, TX 76031 | Oil & Gas Operator | Feb 2026 |
| 312 | Kramer, Clifford A. | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 1997 |
| 313 | KTC Oil Enterprises, LLC | Dallas, TX 75247 | Oil & Gas Operator | Feb 2026 |
| 314 | L.C.S. Production Company | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 315 | La Aceite Energy, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Feb 2026 |
| 316 | Lamesa Crude | Abilene, TX 79605 | Oil & Gas Operator | Feb 2015 |
| 317 | Langford, G. E. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2002 |
| 318 | Lariat Land & Exploration, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 319 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | Feb 2026 |
| 320 | Leonard Brothers Operating Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Feb 2026 |
| 321 | Lesikar, L. W. | Fort Worth, TX 76121 | Oil & Gas Operator | Jun 2006 |
| 322 | Lillis, Michael D. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 323 | Limark Corporation | Midland, TX 79702 | Oil & Gas Operator | Dec 2003 |
| 324 | Logan Energy Co. | Cross Plains, TX 76443 | Oil & Gas Operator | Nov 1997 |
| 325 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 326 | Lone Star Pipeline Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 327 | Lone Star Production | Lawn, TX 79530 | Oil & Gas Operator | Feb 2026 |
| 328 | Lowrance Inc. | Eastland, TX 76448 | Oil & Gas Operator | Feb 2026 |
| 329 | LTS Oil & Gas | Lubbock, TX 79424 | Oil & Gas Operator | Feb 2026 |
| 330 | Lubbock Energy, Inc. | Lubbock, TX 79453 | Oil & Gas Operator | Oct 1996 |
| 331 | Lyndum, Inc. | Weatherford, TX 76088 | Oil & Gas Operator | Oct 2009 |
| 332 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 333 | M & M Oil & Gas Exploration Inc | Abilene, TX 79601 | Oil & Gas Operator | Mar 2008 |
| 334 | M H W, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Jul 1996 |
| 335 | M S B Company | Slaton, TX 79364 | Oil & Gas Operator | Dec 2016 |
| 336 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Feb 2026 |
| 337 | M. Grace, Inc. | Henderson, TX 75653 | Oil & Gas Operator | Feb 2026 |
| 338 | Madera, R. F. | Palm Desert, CA 92210 | Oil & Gas Operator | Sep 2000 |
| 339 | Magna Diversified Group, Inc. | Jacksonville, TX 75766 | Oil & Gas Operator | Oct 2013 |
| 340 | Magnet Oil LP | Bronte, TX 76933 | Oil & Gas Operator | Feb 2026 |
| 341 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 342 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 343 | Marrow, N. S. | Austin, TX 78703 | Oil & Gas Operator | Aug 2012 |
| 344 | Masada Oil & Gas Company LTD. | Abilene, TX 79603 | Oil & Gas Operator | Feb 2026 |
| 345 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 346 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 347 | McCracken, Eugene | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 348 | McIver, Inc | San Angelo, TX 76903 | Oil & Gas Operator | Feb 2026 |
| 349 | McIver, Terry L. | Santa Anna, TX 76878 | Oil & Gas Operator | Aug 2003 |
| 350 | McMoran Oil & Gas LLC | New Orleans, LA 70160 | Oil & Gas Operator | Oct 2021 |
| 351 | McNallen Oil Co., Inc. | Keller, TX 76244 | Oil & Gas Operator | Feb 2026 |
| 352 | Meco IV, LLC | Lakewood, CO 80227 | Oil & Gas Operator | Jul 2021 |
| 353 | Mehaffey Investments, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Feb 2026 |
| 354 | Mercury Exploration Co. | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 355 | Merenco | Midland, TX 79702 | Oil & Gas Operator | Dec 1996 |
| 356 | Merimac Investments, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jan 1997 |
| 357 | Mesa Energy, Inc. | Austin, TX 78755 | Oil & Gas Operator | Dec 2013 |
| 358 | Mid-Tex Energy Inc. | Costa Mesa, CA 92626 | Oil & Gas Operator | Jan 1999 |
| 359 | Midsco | Cross Plains, TX 76443 | Oil & Gas Operator | Feb 2026 |
| 360 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 361 | Miller Operating Company LLC | Lafayette, LA 70598 | Oil & Gas Operator | Feb 2026 |
| 362 | Miller, Donny | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 363 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Feb 2026 |
| 364 | Mingus Oil & Gas | Mingus, TX 76463 | Oil & Gas Operator | Feb 2026 |
| 365 | Minuteman Energy, LLC | Georgetown, TX 78633 | Oil & Gas Operator | Feb 2015 |
| 366 | Mission Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 367 | Mist Prod. & Exploration Corp. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 368 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 369 | Mixon, Robert N. | Lometa, TX 76853 | Oil & Gas Operator | Feb 2026 |
| 370 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 371 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 372 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Dec 2025 |
| 373 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 2007 |
| 374 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 375 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Feb 2026 |
| 376 | Mogul Resources, LLC | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 377 | Mole Hole Prod. | Bridgeport, TX 76426 | Oil Operator | Feb 2026 |
| 378 | Momentum Oil Company | Albany, TX 76430 | Oil & Gas Operator | May 2003 |
| 379 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 380 | Moore Investment Co. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 381 | Morrell, W. R. | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 382 | Morris R. Greenhaw Oil&Gas, Inc | Desdemona, TX 76445 | Oil & Gas Operator | Feb 2026 |
| 383 | Morton Valley Oil & Gas, Inc. | Dallas, TX 75222 | Oil & Gas Operator | Jun 2007 |
| 384 | Mountain Creek Oil Company, Inc. | Saint Jo, TX 76265 | Oil & Gas Operator | Feb 2026 |
| 385 | Moylan, Jimmie C. | Eastland, TX 76448 | Oil & Gas Operator | Feb 2026 |
| 386 | Mustang Oil & Gas Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2021 |
| 387 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Feb 2026 |
| 388 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 389 | Nitschke, Dan E. | Henrietta, TX 76365 | Oil & Gas Operator | Feb 2026 |
| 390 | Nix, Tommy | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 391 | Noramco Production, LLC | Midland, TX 79710 | Oil & Gas Operator | Jan 2023 |
| 392 | Nordan Oil & Gas Corporation | Abilene, TX 79604 | Oil & Gas Operator | Feb 2018 |
| 393 | North American Exploration Co. | Abilene, TX 79602 | Oil & Gas Operator | Apr 1998 |
| 394 | North Ridge Corporation | Duncanville, TX 75137 | Oil & Gas Operator | Feb 2026 |
| 395 | NT Minerals, LLC | Tulsa, OK 74172 | Oil & Gas Operator | Feb 2026 |
| 396 | O.G.O. Refining | Luling, TX 78648 | Oil & Gas Operator | Jun 2013 |
| 397 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Feb 2026 |
| 398 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Feb 2026 |
| 399 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Feb 2026 |
| 400 | Older Than Dirt LLC | Weatherford, TX 76086 | Oil & Gas Operator | Feb 2026 |