| 301 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 302 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 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 | Kimbrel Oil Corporation | Tulsa, OK 74114 | Oil & Gas Operator | May 2025 |
| 306 | Klingberg, Roger | Cross Plains, TX 76443 | Oil & Gas Operator | Jan 2017 |
| 307 | Kokomo Energy, Inc. | Gorman, TX 76454 | Oil & Gas Operator | May 2025 |
| 308 | Kornye-Tillman Company | Cleburne, TX 76031 | Oil & Gas Operator | May 2025 |
| 309 | Kramer Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 310 | Kramer, Frank & Ethel FLP | Graham, TX 76450 | Oil & Gas Operator | Sep 2014 |
| 311 | Kramer, Frank C. | Graham, TX 76450 | Oil & Gas Operator | Apr 2004 |
| 312 | Kroh Operating LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 313 | L & R Energy Corporation | Spearman, TX 79081 | Oil & Gas Operator | Nov 2014 |
| 314 | L.C.S. Production Company | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 315 | Lakeshore Operating, LLC | Wichita, KS 67203 | Oil & Gas Operator | May 2025 |
| 316 | Laneer Resources Company | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 317 | Langford, G. E. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2002 |
| 318 | Largo Oil Company | Longview, TX 75606 | Oil & Gas Operator | May 2025 |
| 319 | Layline Petroleum I, LLC | Houston, TX 77024 | Oil & Gas Operator | May 2013 |
| 320 | Leading Edge Energy LLC | San Antonio, TX 78205 | Oil Operator | May 2025 |
| 321 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | May 2025 |
| 322 | Ledbetter, Jerald D. Estate Of | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 323 | Ledbetter, Jerald D. Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jan 2007 |
| 324 | Leigh Operating Co | Dallas, TX 75205 | Oil & Gas Operator | Mar 2008 |
| 325 | Leonard Brothers Operating Co. | Fort Worth, TX 76101 | Oil & Gas Operator | May 2025 |
| 326 | Liberty Resources Co. | Big Lake, TX 76932 | Oil & Gas Operator | Mar 1994 |
| 327 | Lime Rock Resources A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 328 | Littlepage, Tommy | Graham, TX 76450 | Oil & Gas Operator | May 1996 |
| 329 | Llewellin Operating Company, LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2017 |
| 330 | Lobo Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 331 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 332 | Lone Star Pipeline Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 333 | Long Trusts, The | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 334 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 335 | Lowrance Inc. | Eastland, TX 76448 | Oil & Gas Operator | May 2025 |
| 336 | LSM Ventures, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 2020 |
| 337 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 338 | Lyon Operating Company Inc.(Iii) | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 339 | Lytle Creek Operating, Inc. | Abilene, TX 79606 | Oil & Gas Operator | May 2025 |
| 340 | M H W, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Jul 1996 |
| 341 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 342 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |
| 343 | Marbil Oil, Inc. | Olney, TX 76374 | Oil & Gas Operator | Jun 2013 |
| 344 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 345 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 346 | Marshall Pipe & Supply Co. | Nocona, TX 76255 | Oil & Gas Operator | Mar 2008 |
| 347 | Martin Petroleum Corp. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 348 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 349 | Mayes Operating Co. | Stephenville, TX 76401 | Oil & Gas Operator | Oct 2019 |
| 350 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | May 2025 |
| 351 | McBride Production Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 1993 |
| 352 | McClymond, B. W. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2020 |
| 353 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 354 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 355 | McCrea Exploration Company, Inc. | Carrollton, TX 75007 | Oil & Gas Operator | Nov 1995 |
| 356 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 357 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 358 | McNallen & Griffin | Keller, TX 76244 | Oil & Gas Operator | May 2025 |
| 359 | McNallen Oil Co., Inc. | Keller, TX 76244 | Oil & Gas Operator | May 2025 |
| 360 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 361 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 362 | Mehaffey Investments, Inc. | Eastland, TX 76448 | Oil & Gas Operator | May 2025 |
| 363 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 364 | Merrimac Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 365 | Mesquite Oil & Gas Production | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 366 | Micro Operating, Inc. | Bryan, TX 77807 | Oil & Gas Operator | May 2025 |
| 367 | Midville Energy, LLC. | Midland, TX 79705 | Oil & Gas Operator | Jul 2024 |
| 368 | Miller, Bob I. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 369 | Mingus Oil & Gas | Mingus, TX 76463 | Oil & Gas Operator | May 2025 |
| 370 | Misener Operating, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2010 |
| 371 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 372 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 373 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | May 2025 |
| 374 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 375 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2025 |
| 376 | Mogul Resources, LLC | Cisco, TX 76437 | Oil & Gas Operator | May 2025 |
| 377 | Momentum Oil Company | Albany, TX 76430 | Oil & Gas Operator | May 2003 |
| 378 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 379 | Montgomery Royalty | Moran, TX 76464 | Oil & Gas Operator | May 2025 |
| 380 | Moore, Stephen Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 381 | Mormar Family Holdings, L.L.C. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 382 | Morton Valley Oil & Gas, Inc. | Dallas, TX 75222 | Oil & Gas Operator | Jun 2007 |
| 383 | Mustang Oil & Gas Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2021 |
| 384 | N. E. Operating Co., Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2013 |
| 385 | Nall Oil & Gas | Mineral Wells, TX 76067 | Oil & Gas Operator | May 2025 |
| 386 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 387 | Natural Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jul 1997 |
| 388 | Navus Operating, Inc. | Dallas, TX 75367 | Oil & Gas Operator | May 2025 |
| 389 | Nec Operating, LLC | Southlake, TX 76092 | Oil & Gas Operator | May 2025 |
| 390 | Necessity Well Service | Breckenridge, TX 76424 | Oil & Gas Operator | Jan 1994 |
| 391 | Necessity Well Service, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2006 |
| 392 | Neeley, June | Mineral Wells, TX 76067 | Oil & Gas Operator | Feb 2008 |
| 393 | New Era International | Graham, TX 76450 | Oil & Gas Operator | Sep 2017 |
| 394 | New Horizon Exploration, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Jun 2006 |
| 395 | Ngezi, LCC | Fort Worth, TX 76111 | Oil & Gas Operator | May 2025 |
| 396 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 397 | Nick Oil | Abilene, TX 79601 | Oil & Gas Operator | May 2025 |
| 398 | Nitschke, Dan E. | Henrietta, TX 76365 | Oil & Gas Operator | May 2025 |
| 399 | North American Drilling Corp | Plano, TX 75093 | Oil & Gas Operator | May 2025 |
| 400 | North Central Casing Pullers,Inc | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |