| 301 | L R Operating Co. | Graford, TX 76449 | Oil & Gas Operator | Jun 2025 |
| 302 | L-Reno Oil And Gas LLC | Graford, TX 76449 | Oil & Gas Operator | Dec 2025 |
| 303 | L.C.S. Production Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 304 | L.J. Resources, LLC | Graham, TX 76450 | Gas Operator | Dec 2025 |
| 305 | Langford, G. E. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2002 |
| 306 | Lankford, Dan L. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 307 | Lariat Land & Exploration, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 308 | Lavanco Energy, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2006 |
| 309 | Lavanco Energy, LTD. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2024 |
| 310 | Laws Exploration LLC | Mineral Wells, TX 76067 | Oil & Gas Operator | Dec 2025 |
| 311 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | Dec 2025 |
| 312 | Leclair Operating, L.L.C. | Abilene, TX 79602 | Oil & Gas Operator | Dec 2025 |
| 313 | Lexgas, Inc. | Roanoke, TX 76262 | Oil & Gas Operator | Dec 2025 |
| 314 | Lexus Gas Corporation | Roanoke, TX 76262 | Oil & Gas Operator | Jul 2005 |
| 315 | Littlepage, Tommy | Graham, TX 76450 | Oil & Gas Operator | May 1996 |
| 316 | Live Oak Gas Company | Dallas, TX 75251 | Oil & Gas Operator | Dec 2025 |
| 317 | LMG Operating Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2007 |
| 318 | Lowrance & Ray Exploration, Inc. | Fort Worth, TX 76147 | Oil & Gas Operator | Sep 2003 |
| 319 | Lowrance Inc. | Eastland, TX 76448 | Oil & Gas Operator | Dec 2025 |
| 320 | Lyndum, Inc. | Weatherford, TX 76088 | Oil & Gas Operator | Oct 2009 |
| 321 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2025 |
| 322 | Mac Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2023 |
| 323 | Maddux Oil & Gas | Strawn, TX 76475 | Oil & Gas Operator | Dec 2025 |
| 324 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Nov 2025 |
| 325 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 326 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2025 |
| 327 | Martin Petroleum Corp. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 328 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 329 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Dec 2025 |
| 330 | Mays Enterprises, Inc. | Mineral Wells, TX 76067 | Gas Operator | Oct 2010 |
| 331 | McClure, J.D. Trust | Denton, TX 76209 | Oil & Gas Operator | Dec 2025 |
| 332 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 333 | McCown Engineering | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2025 |
| 334 | McCracken, H. L. Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 335 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Dec 2025 |
| 336 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 337 | McKenzie Operating Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 338 | McMahon-Bullington Drilling Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 1996 |
| 339 | McMahon-Bullington LP | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2009 |
| 340 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 341 | Meeker & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 342 | Megargel Drilling Company | Megargel, TX 76370 | Oil Operator | Nov 1998 |
| 343 | Melrose Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2011 |
| 344 | Merenco | Midland, TX 79702 | Oil & Gas Operator | Dec 1996 |
| 345 | Merimac Investments, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jan 1997 |
| 346 | Merrimac Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 347 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 348 | Miller Operating Company LLC | Lafayette, LA 70598 | Oil & Gas Operator | Dec 2025 |
| 349 | Mills Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 350 | Mills, H. E. | Lipan, TX 76462 | Oil & Gas Operator | Sep 2004 |
| 351 | Mingus Oil & Gas | Mingus, TX 76463 | Oil & Gas Operator | Dec 2025 |
| 352 | Minton Oil & Gas Properties | Graford, TX 76449 | Gas Operator | Dec 2025 |
| 353 | Minuteman Energy, LLC | Georgetown, TX 78633 | Oil & Gas Operator | Feb 2015 |
| 354 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 355 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 356 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 357 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Oct 2025 |
| 358 | Mogul Resources, LLC | Cisco, TX 76437 | Oil & Gas Operator | Dec 2025 |
| 359 | Mole Hole Prod. | Bridgeport, TX 76426 | Oil Operator | Dec 2025 |
| 360 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | Dec 2025 |
| 361 | Mont-Land Co. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 362 | Moore, Miles Inc. | Moran, TX 76464 | Oil & Gas Operator | Dec 2025 |
| 363 | Moore, Stephen Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 364 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Dec 2025 |
| 365 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | Dec 2025 |
| 366 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Dec 2025 |
| 367 | N. A. Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | Dec 2007 |
| 368 | Nall Oil & Gas | Mineral Wells, TX 76067 | Oil & Gas Operator | Dec 2025 |
| 369 | Necessity Well Service, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2006 |
| 370 | Neeley, June | Mineral Wells, TX 76067 | Oil & Gas Operator | Feb 2008 |
| 371 | Ness Operating Of Texas, Inc. | Weatherford, TX 76087 | Oil & Gas Operator | Dec 2004 |
| 372 | Newark E&P Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2017 |
| 373 | Newark Energy LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2011 |
| 374 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 375 | Nokusu, LTD. | Dallas, TX 75231 | Oil & Gas Operator | Sep 2008 |
| 376 | Nordan Oil & Gas Corporation | Abilene, TX 79604 | Oil & Gas Operator | Feb 2018 |
| 377 | Nordstrand Engineering Inc | Houston, TX 77019 | Oil & Gas Operator | Dec 2025 |
| 378 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | Dec 2025 |
| 379 | North Ridge Corporation | Duncanville, TX 75137 | Oil & Gas Operator | Dec 2025 |
| 380 | North Star Energy, Inc. | Strawn, TX 76475 | Oil & Gas Operator | Jan 2010 |
| 381 | North Texas Llano Operating Corp | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 382 | North Texas Plugging, LLC | Denton, TX 76205 | Oil & Gas Operator | Dec 2025 |
| 383 | Novo Exploration Corporation | Hurst, TX 76053 | Oil & Gas Operator | Jun 2020 |
| 384 | NWG Operating LLC | Canyon, TX 79015 | Oil & Gas Operator | Dec 2025 |
| 385 | Oak Hills Drilling & Oper., LLC | Holdenville, OK 74848 | Oil & Gas Operator | May 2013 |
| 386 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2025 |
| 387 | Oasis Operating, Inc. | Lubbock, TX 79404 | Oil & Gas Operator | Nov 2020 |
| 388 | Oil & Gas Field Services LLC | San Felipe, TX 77473 | Oil & Gas Operator | Apr 2007 |
| 389 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 390 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Dec 2025 |
| 391 | Oilwell Operators, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2025 |
| 392 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2025 |
| 393 | Older Than Dirt LLC | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2025 |
| 394 | Ole Chaparral On Possum Kingdom | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1997 |
| 395 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 396 | Orth Oil Company, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Dec 2025 |
| 397 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 398 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Dec 2025 |
| 399 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 400 | P & M Construction | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |