| 301 | Kar Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | May 2025 |
| 302 | Karper Oil & Gas Corporation | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 303 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Feb 2025 |
| 304 | Ken Petroleum Corporation | Dallas, TX 75206 | Oil & Gas Operator | Feb 2019 |
| 305 | Kennemer, Darrell | Boyd, TX 76023 | Oil Operator | May 2025 |
| 306 | Kimleco Petroleum, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2025 |
| 307 | Klein, J. L. | Henrietta, TX 76365 | Oil & Gas Operator | Sep 2013 |
| 308 | Knight, Reuben B. | Windthorst, TX 76389 | Oil & Gas Operator | May 2025 |
| 309 | Kramer, Clifford A. | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 1997 |
| 310 | Kroh Operating LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 311 | Krot Oil Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 312 | KTC Oil Enterprises, LLC | Dallas, TX 75247 | Oil & Gas Operator | May 2025 |
| 313 | Kuehne Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 314 | Kuykendall, IValene Estate | Electra, TX 76360 | Oil & Gas Operator | Dec 1998 |
| 315 | Kuykendall, M. C. | Electra, TX 76360 | Oil & Gas Operator | Apr 1995 |
| 316 | Kuykendall, M.C., Estate | Electra, TX 76360 | Oil & Gas Operator | Aug 2003 |
| 317 | L L & M Properties, Inc. | Burkburnett, TX 76354 | Oil & Gas Operator | Aug 2004 |
| 318 | Landrum Petroleum Co., Inc. | Burkburnett, TX 76354 | Oil Operator | Mar 2008 |
| 319 | Landrum West, Inc. | Burkburnett, TX 76354 | Oil & Gas Operator | Dec 1997 |
| 320 | Landrum, W. A. | Byers, TX 76357 | Oil & Gas Operator | Apr 2002 |
| 321 | Lane Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2025 |
| 322 | Larance Engineering Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Jan 1996 |
| 323 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 324 | LC Operating, LLC | Burkburnett, TX 76354 | Oil & Gas Operator | May 2025 |
| 325 | Legacy Exploration, LLC I | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 326 | Lewis Operating Company | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 327 | Liberty Operating Company, Inc. | Lake Dallas, TX 75065 | Oil & Gas Operator | Mar 2008 |
| 328 | Lindemann, James D. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 329 | Lindemann, Robert Operating | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 330 | Lindemann, W. L., DRLG. Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 1994 |
| 331 | Lindemann, W.L., Oper. Co., Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2006 |
| 332 | Lindsay Oil Operations | Wichita Falls, TX 76310 | Oil & Gas Operator | Jun 2010 |
| 333 | Live Oak Gas Company | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 334 | LMH Energy | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 335 | Lofton, W. A. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 1998 |
| 336 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 337 | Lone Star Land And Energy II LLC | Dallas, TX 75214 | Oil & Gas Operator | Jan 2020 |
| 338 | Lone Star Pipeline Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 339 | Longhorn Oil Properties, Inc. | Pottsboro, TX 75076 | Oil & Gas Operator | May 2025 |
| 340 | Low-End Oil LLC | Austin, TX 78748 | Oil Operator | May 2025 |
| 341 | Lufkin Production Company Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 342 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 343 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 344 | Lyon Operating Company Inc.(Iii) | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 345 | M & A Oil Company, LTD. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 346 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | May 2025 |
| 347 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | May 2025 |
| 348 | Macha Enterprises, Inc. | Wichita Falls, TX 76309 | Oil Operator | May 2025 |
| 349 | Maddox Operating | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 350 | Maledon Enterprises | Austin, TX 78738 | Oil & Gas Operator | Feb 1996 |
| 351 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 352 | Maranatha Exploration, LP | Wichita Falls, TX 76307 | Oil Operator | Feb 2012 |
| 353 | Marata Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Aug 2003 |
| 354 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 355 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 356 | Marshall Energy, Inc. | Dallas, TX 75243 | Oil & Gas Operator | May 1997 |
| 357 | Massie Oil Company | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 358 | Mayco Oil | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 359 | Mayo, Keith | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 2009 |
| 360 | MB Operating | Wichita Falls, TX 76309 | Oil & Gas Operator | Mar 2008 |
| 361 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 362 | McCauley Production | Graham, TX 76450 | Oil Operator | May 2025 |
| 363 | McCormick Operating, L.L.C. | Olney, TX 76374 | Oil Operator | Sep 2015 |
| 364 | McCown Engineering | Wichita Falls, TX 76310 | Oil & Gas Operator | May 2025 |
| 365 | McDay Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 366 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 367 | Menasco, J. | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2019 |
| 368 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 369 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | May 2025 |
| 370 | Metzner, Norma J. Estate | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 1998 |
| 371 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 2025 |
| 372 | Midnite Oil Co. | Wichita Falls, TX 76310 | Oil & Gas Operator | May 2025 |
| 373 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 374 | Miller, Glenn J. | Muenster, TX 76252 | Oil & Gas Operator | May 2025 |
| 375 | Mills Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 376 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 377 | Mobil Petro Vac, Inc. | Duncan, OK 73533 | Oil & Gas Operator | May 2025 |
| 378 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2025 |
| 379 | Mobile Petrovac, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 380 | Moller, Herbert T. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2003 |
| 381 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 382 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 383 | Mountain Creek Oil Company, Inc. | Saint Jo, TX 76265 | Oil & Gas Operator | May 2025 |
| 384 | Muenster Drilling Co. Inc. | Muenster, TX 76252 | Oil & Gas Operator | May 2025 |
| 385 | Muirfield Exploration, LTD. | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2025 |
| 386 | Ness Operating Of Texas, Inc. | Weatherford, TX 76087 | Oil & Gas Operator | Dec 2004 |
| 387 | Newton Corp.,The | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 388 | Newton, Richard R. | Wichita Falls, TX 76309 | Oil & Gas Operator | Nov 1996 |
| 389 | NHRG Inc | Wichita Falls, TX 76308 | Oil Operator | May 2025 |
| 390 | Nortex Energy, Inc. | Muenster, TX 76252 | Oil Operator | May 2025 |
| 391 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 392 | Northridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 393 | O'Donohoe, Jack | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2002 |
| 394 | O'Neal Oil Company | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 395 | O'Neal, Lindell | Nocona, TX 76255 | Oil & Gas Operator | Mar 2025 |
| 396 | Oakridge Energy, Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | May 2025 |
| 397 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 398 | Oriole Operating LLC | Wichita Falls, TX 76308 | Oil Operator | May 2025 |
| 399 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | May 2025 |
| 400 | Parnell Operating | Kamay, TX 76369 | Oil & Gas Operator | May 2025 |