| 301 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 302 | Lone Star Production | Lawn, TX 79530 | Oil & Gas Operator | Jul 2025 |
| 303 | Low-End Oil LLC | Austin, TX 78748 | Oil Operator | Jul 2025 |
| 304 | LTS Oil & Gas | Lubbock, TX 79424 | Oil & Gas Operator | Jul 2025 |
| 305 | Lumbley, W. F. | Hobbs, NM 88242 | Oil & Gas Operator | Jan 2008 |
| 306 | Lynx Oil Co., Inc. | Denton, TX 76207 | Oil & Gas Operator | Sep 2003 |
| 307 | Lytle Creek Operating, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Jul 2025 |
| 308 | M E Klein & Associates, Inc. | Norman, OK 73070 | Oil & Gas Operator | Mar 2025 |
| 309 | M.R.M. Operating, Inc. | Midland, TX 79707 | Oil & Gas Operator | Aug 2003 |
| 310 | Magnet Oil LP | Bronte, TX 76933 | Oil & Gas Operator | Jul 2025 |
| 311 | Mammoth Operating LLC | Spicewood, TX 78669 | Oil Operator | Jul 2025 |
| 312 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 313 | Marianas Operating Co. | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 314 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2025 |
| 315 | Mark IV Energy | San Antonio, TX 78213 | Oil & Gas Operator | Apr 1993 |
| 316 | Martin, Jimmy Inc | San Angelo, TX 76904 | Oil & Gas Operator | Jul 2025 |
| 317 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 2025 |
| 318 | Masters Rat Hole Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 319 | Mathis, Bill | Midland, TX 79702 | Oil & Gas Operator | Nov 2001 |
| 320 | Maxwell, Riley G., Co. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 321 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 322 | McBee, Jim Co. | Santa Anna, TX 76878 | Oil & Gas Operator | Mar 2012 |
| 323 | McIver, Inc | San Angelo, TX 76903 | Oil & Gas Operator | Jul 2025 |
| 324 | McIver, Terry L. | Santa Anna, TX 76878 | Oil & Gas Operator | Aug 2003 |
| 325 | McLain Exploration, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Mar 2008 |
| 326 | McMurrey, R. J., Production Comp | Tyler, TX 75711 | Oil & Gas Operator | Jul 2025 |
| 327 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 328 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Jul 2025 |
| 329 | Mid Texas Natural Gas | Kyle, TX 78640 | Oil & Gas Operator | May 2019 |
| 330 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2025 |
| 331 | Mid-Tex Energy Inc. | Costa Mesa, CA 92626 | Oil & Gas Operator | Jan 1999 |
| 332 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 333 | Mineral Development, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1996 |
| 334 | Minuteman Energy, LLC | Georgetown, TX 78633 | Oil & Gas Operator | Feb 2015 |
| 335 | Mission Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 336 | MMG Oil Company | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2006 |
| 337 | Mole Hole Prod. | Bridgeport, TX 76426 | Oil Operator | Jul 2025 |
| 338 | Moleco, LLC | Santa Anna, TX 76878 | Oil Operator | Jul 2025 |
| 339 | Mondiale Energy, Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Jul 2025 |
| 340 | Moore Investment Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 341 | Morgan Creek Production Co., Inc | Westbrook, TX 79565 | Oil & Gas Operator | Jul 2025 |
| 342 | Morrell, W. R. | Albany, TX 76430 | Oil & Gas Operator | Jul 2025 |
| 343 | Morris Operating Co | Lovington, NM 88260 | Oil & Gas Operator | Jul 2025 |
| 344 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Jul 2025 |
| 345 | Mudslinger Oil, L.L.C. | Abilene, TX 79601 | Oil Operator | Jul 2025 |
| 346 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Jul 2025 |
| 347 | My Hop Mineral | Moorhead, MN 56560 | Oil & Gas Operator | Jul 2025 |
| 348 | Nautilus Exploration, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Nov 2021 |
| 349 | Neeb, H. L. | Abilene, TX 79606 | Oil & Gas Operator | Jul 1994 |
| 350 | Nev-Tex Oil & Gas, Inc. | Reno, NV 89504 | Oil & Gas Operator | Jul 2025 |
| 351 | New Horizon Exploration, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Jun 2006 |
| 352 | Newman & Scott | Duncan, OK 73534 | Oil & Gas Operator | Mar 2024 |
| 353 | Newman, John A. | Joplin, MO 64804 | Oil & Gas Operator | Jan 2001 |
| 354 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 355 | Nolen, Charles R. | San Angelo, TX 76904 | Oil & Gas Operator | Dec 2006 |
| 356 | Northcutt Production | Bangs, TX 76823 | Oil & Gas Operator | Jul 2025 |
| 357 | Nosivad Oil, Inc. | Clyde, TX 79510 | Oil & Gas Operator | Jul 2025 |
| 358 | Novco Operating Company | Novice, TX 79538 | Oil & Gas Operator | Jul 2025 |
| 359 | Novo Exploration Corporation | Hurst, TX 76053 | Oil & Gas Operator | Jun 2020 |
| 360 | O Hill Enterprises, Inc. | La Grange, TX 78945 | Oil & Gas Operator | Jan 2014 |
| 361 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 362 | Ogden Resources Corporation | Bryan, TX 77802 | Oil & Gas Operator | Jul 2025 |
| 363 | Ogden Resources, LTD. | Bryan, TX 77802 | Oil & Gas Operator | Feb 2009 |
| 364 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 365 | Oil & Gas Properties | Midland, TX 79704 | Oil & Gas Operator | Jul 2025 |
| 366 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 367 | Oil Projects, LLC | Houston, TX 77027 | Oil & Gas Operator | Jul 2025 |
| 368 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Jul 2025 |
| 369 | Ojb, Inc. | Buda, TX 78610 | Oil & Gas Operator | Mar 2013 |
| 370 | Older Than Dirt LLC | Palo Pinto, TX 76484 | Oil & Gas Operator | Jul 2025 |
| 371 | Orland Oil & Gas LLC | FT Lauderdale, FL 33305 | Oil Operator | Aug 2024 |
| 372 | Orth Oil Company, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Jul 2025 |
| 373 | Otex LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Jul 2025 |
| 374 | Ouida Oil | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2008 |
| 375 | Overland Operating Company, LLC | Abilene, TX 79601 | Oil Operator | Jul 2025 |
| 376 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 377 | P-Tex Petroleum, Inc. | Dallas, TX 75238 | Oil & Gas Operator | Nov 1999 |
| 378 | P.B. Blue Dot Properties | Wexford, PA 15090 | Oil & Gas Operator | Jul 2025 |
| 379 | Pace Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Jul 2025 |
| 380 | Pace Production Co. | San Angelo, TX 76902 | Oil & Gas Operator | Jul 2025 |
| 381 | Palo Petroleum, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jul 2025 |
| 382 | Pan Petroleum Corp. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2008 |
| 383 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Jul 2025 |
| 384 | Parabellum Energy Oper Co, LLC | Houston, TX 77056 | Oil Operator | Dec 2017 |
| 385 | Paragon Corporation | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 386 | Parallel Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Jan 2010 |
| 387 | Parker Operating Co., Inc. | Aledo, TX 76008 | Oil & Gas Operator | Sep 2000 |
| 388 | Patriot Services, Inc. | Westbrook, TX 79565 | Oil & Gas Operator | Mar 2008 |
| 389 | Patton Coleman Exploration Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 390 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 391 | Ped Oil Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 392 | Penntex Resources, L.P. | State College, PA 16803 | Oil & Gas Operator | Mar 2016 |
| 393 | Petro 2000 Exploration Co. | Katy, TX 77450 | Oil & Gas Operator | Nov 2011 |
| 394 | Petro-Beth Oil & Gas, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2006 |
| 395 | Petroleum Capital, L.C. | Dallas, TX 75367 | Oil & Gas Operator | Jul 2025 |
| 396 | Petrotex, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 397 | Pillows, Burl A. | Houston, TX 77062 | Oil & Gas Operator | Jul 2025 |
| 398 | Pinon Petroleum, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Apr 2004 |
| 399 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | May 2025 |
| 400 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |