| 301 | K-B Oil Company | Dallas, TX 75243 | Oil & Gas Operator | Dec 2020 |
| 302 | K-B Oil Company, LLC | Dallas, TX 75243 | Oil & Gas Operator | Dec 2024 |
| 303 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Dec 2024 |
| 304 | Karper Company, The | Graham, TX 76450 | Oil & Gas Operator | Feb 2003 |
| 305 | Karper Oil & Gas Corporation | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 306 | Kec Enterprises, Inc. | Springtown, TX 76082 | Oil & Gas Operator | Dec 2024 |
| 307 | Keene, Roy J. Jr. | Sugar Land, TX 77498 | Oil & Gas Operator | Jun 2016 |
| 308 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Jun 2024 |
| 309 | Kimleco Petroleum, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Dec 2024 |
| 310 | KLM Petroleum Corp. | Midland, TX 79705 | Oil & Gas Operator | Dec 2024 |
| 311 | KND Oil & Gas, LLC | Jacksboro, TX 76458 | Oil & Gas Operator | Nov 2023 |
| 312 | Knight, Reuben B. | Windthorst, TX 76389 | Oil & Gas Operator | Dec 2024 |
| 313 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2024 |
| 314 | Koram Operating LLC | Houston, TX 77079 | Oil & Gas Operator | Dec 2006 |
| 315 | Kroh Operating LLC | Fort Worth, TX 76114 | Oil & Gas Operator | Dec 2024 |
| 316 | KTC Oil Enterprises, LLC | Dallas, TX 75247 | Oil & Gas Operator | Dec 2024 |
| 317 | L A Productions | Sunset, TX 76270 | Oil & Gas Operator | Dec 2024 |
| 318 | Lakota Energy, LTD. | Paradise, TX 76073 | Oil & Gas Operator | Dec 2024 |
| 319 | Large Operating LLC | Stinnett, TX 79083 | Oil & Gas Operator | Dec 2024 |
| 320 | Latigo Oil And Gas Inc | Woodward, OK 73801 | Oil & Gas Operator | Oct 2024 |
| 321 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | Dec 2024 |
| 322 | Legacy Exploration, LLC I | Dallas, TX 75201 | Oil & Gas Operator | Dec 2024 |
| 323 | Legend Natural Gas IV, LP | Houston, TX 77094 | Oil & Gas Operator | Feb 2015 |
| 324 | Legend Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | May 2010 |
| 325 | Lime Rock Resources IV-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 326 | Lindsay Oil Operations | Wichita Falls, TX 76310 | Oil & Gas Operator | Jun 2010 |
| 327 | Lindsay, Robert L. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 1995 |
| 328 | Littlepage, Tommy | Graham, TX 76450 | Oil & Gas Operator | May 1996 |
| 329 | LKM Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2024 |
| 330 | Llewellin Operating Company, LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2017 |
| 331 | London Petroleum Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2024 |
| 332 | Loutex Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2024 |
| 333 | Lowrance, Gene | Chico, TX 76431 | Oil & Gas Operator | Aug 2003 |
| 334 | Luxor Oil & Gas, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Mar 2017 |
| 335 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 336 | Mahfouz Energy Company | Houston, TX 77255 | Oil & Gas Operator | Nov 2020 |
| 337 | Mar Oil & Gas Corp. | Santa Fe, NM 87502 | Oil & Gas Operator | Sep 2024 |
| 338 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 339 | Marrow, N. S. | Austin, TX 78703 | Oil & Gas Operator | Aug 2012 |
| 340 | Martex Oil & Gas, Inc. | Estes Park, CO 80517 | Oil & Gas Operator | Dec 2024 |
| 341 | Maxey & Swan Oil Co. | Decatur, TX 76234 | Oil & Gas Operator | Apr 2007 |
| 342 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 343 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 344 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 345 | McCommons Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2024 |
| 346 | McCracken, H. L. Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2024 |
| 347 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jul 2024 |
| 348 | McCutchin Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 349 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 350 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 351 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 352 | McGuire Brothers | Phoenix, AZ 85045 | Oil & Gas Operator | Dec 2024 |
| 353 | MDM Energy, Inc. | The Colony, TX 75056 | Oil & Gas Operator | Dec 2024 |
| 354 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 355 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 356 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 357 | Merritt Operating, Inc. | Mineola, TX 75773 | Oil & Gas Operator | Dec 2024 |
| 358 | Messy Oil And Gas, LLC | Garwood, TX 77442 | Oil & Gas Operator | Dec 2024 |
| 359 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 360 | Mid Texas Natural Gas | Kyle, TX 78640 | Oil & Gas Operator | May 2019 |
| 361 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 362 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 363 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 364 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 365 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 366 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 367 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 368 | Mobil Petro Vac, Inc. | Duncan, OK 73533 | Oil & Gas Operator | Dec 2024 |
| 369 | Monitor O&G, L.L.C. | Frisco, TX 75034 | Oil & Gas Operator | Jan 2016 |
| 370 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 371 | Moriah Resources, Inc. | Midland, TX 79704 | Oil & Gas Operator | Mar 2008 |
| 372 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Dec 2024 |
| 373 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 374 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Jul 2024 |
| 375 | Myers, A. J. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2024 |
| 376 | Myung And Associates, Inc. | Houston, TX 77056 | Oil & Gas Operator | May 2000 |
| 377 | Nautilus Exploration, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Nov 2021 |
| 378 | Navus Operating, Inc. | Dallas, TX 75367 | Oil & Gas Operator | Dec 2024 |
| 379 | NBL Permian LLC | Houston, TX 77070 | Oil & Gas Operator | Aug 2018 |
| 380 | Nec Operating, LLC | Southlake, TX 76092 | Oil & Gas Operator | Dec 2024 |
| 381 | Newark E&P Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2017 |
| 382 | Newton Corp.,The | Dallas, TX 75251 | Oil & Gas Operator | Dec 2024 |
| 383 | North Central Oil Corp. | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 384 | North Texas Llano Operating Corp | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 385 | Northridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2024 |
| 386 | Now Development Co., Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2017 |
| 387 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 388 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2024 |
| 389 | Oleum Partners, LLC | Frisco, TX 75034 | Oil & Gas Operator | Dec 2024 |
| 390 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 391 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 392 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 393 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 394 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Dec 2024 |
| 395 | P. L. O. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2016 |
| 396 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Dec 2024 |
| 397 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 398 | Pantex Oil & Gas LLC | Ranger, TX 76470 | Oil & Gas Operator | Jul 2018 |
| 399 | Panther Creek Resources, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2012 |
| 400 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |