| 301 | Northridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2025 |
| 302 | Now Development Co., Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2017 |
| 303 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Jul 2025 |
| 304 | Oak Hills Drilling & Oper., LLC | Holdenville, OK 74848 | Oil & Gas Operator | May 2013 |
| 305 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Jul 2025 |
| 306 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2025 |
| 307 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 308 | Omega Energy, LLC | Corpus Chrsti, TX 78418 | Oil & Gas Operator | Jul 2025 |
| 309 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Jul 2025 |
| 310 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 311 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | Jul 2025 |
| 312 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 313 | Ozark Exploration, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jul 2025 |
| 314 | P-R-O Management, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 315 | P. L. O. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2016 |
| 316 | Pace Oil And Gas Company | Austin, TX 78715 | Oil & Gas Operator | Jul 2025 |
| 317 | Pack-Man Energy Company | Ranger, TX 76470 | Oil & Gas Operator | Nov 2005 |
| 318 | Palmigo Oil Co. | West Hills, CA 91308 | Oil & Gas Operator | Oct 2017 |
| 319 | Palo Cross, LLC | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 320 | Palo Petroleum, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jul 2025 |
| 321 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Jul 2025 |
| 322 | Panther Creek Resources, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2012 |
| 323 | Paradigm Petroleum Corporation | Abilene, TX 79605 | Oil & Gas Operator | Jul 2025 |
| 324 | Paragon Oil & Gas, LLC | Aledo, TX 76008 | Oil & Gas Operator | Jul 2025 |
| 325 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 326 | Patton, Lloyd | Fort Worth, TX 76113 | Oil & Gas Operator | Aug 2003 |
| 327 | Pawnee Oil And Gas, Inc. | Richardson, TX 75083 | Oil & Gas Operator | May 2023 |
| 328 | Peba Oil & Gas Co. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jun 2015 |
| 329 | Peba Oil & Gas, Inc. | Nocona, TX 76255 | Oil & Gas Operator | Jul 2025 |
| 330 | Pecos Valley Management Co. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2008 |
| 331 | Pendragon Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jul 2025 |
| 332 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | May 2025 |
| 333 | Peters Petroleum Corporation | Dallas, TX 75243 | Oil & Gas Operator | Jan 2014 |
| 334 | Peterson Oil And Gas LLC | Wichita Falls, TX 76310 | Oil & Gas Operator | Jul 2025 |
| 335 | Phillips, Bob | Weatherford, TX 76086 | Oil & Gas Operator | Nov 2019 |
| 336 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 337 | Plover Production Company | Fort Worth, TX 76109 | Oil & Gas Operator | Jul 2006 |
| 338 | Porter, James W. Special | Blanco, TX 78606 | Oil & Gas Operator | Jul 2025 |
| 339 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Jul 2025 |
| 340 | Prairie Energy Company | Fort Worth, TX 76185 | Oil & Gas Operator | Mar 2003 |
| 341 | Prairie Petroleum, Inc | Plano, TX 75093 | Oil & Gas Operator | May 1999 |
| 342 | Premier Natural Resources II,LLC | Tulsa, OK 74105 | Oil & Gas Operator | Feb 2015 |
| 343 | Premier Oil & Gas LLC | Blanchard, OK 73010-2010 | Oil Operator | Dec 2022 |
| 344 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2024 |
| 345 | Proco Operating Co., Inc. | Graford, TX 76449 | Oil & Gas Operator | Jul 2025 |
| 346 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Jul 2025 |
| 347 | Pursley, John | Jacksboro, TX 76458 | Oil & Gas Operator | Jul 2025 |
| 348 | Quest Petroleum Company | Jacksboro, TX 76458 | Oil & Gas Operator | Jul 2025 |
| 349 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 350 | R. & R. Exploration, Inc. | Denton, TX 76202 | Oil Operator | Nov 1993 |
| 351 | R.E.D. Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2004 |
| 352 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 353 | Ranger Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 354 | Ratts, Robert V. Inc. | Bedford, TX 76021 | Oil & Gas Operator | Aug 2003 |
| 355 | Raylee Operating Company | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 356 | Red Dove Oil & Gas, LLC | Mineral Wells, TX 76067 | Gas Operator | Jul 2025 |
| 357 | Red Stag Energy, LLC | Ozona, TX 76943 | Oil & Gas Operator | Jan 2022 |
| 358 | Regal Energy Operating, L.L.C. | Plano, TX 75024 | Oil & Gas Operator | Jul 2025 |
| 359 | Regal Petroleum Services | Euless, TX 76039 | Oil & Gas Operator | Aug 2002 |
| 360 | Regency Petroleum Co. Of New Mex | Coppell, TX 75019 | Oil & Gas Operator | Apr 2008 |
| 361 | Reichmann Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Jul 2025 |
| 362 | Reostar Operating Incorporated | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2012 |
| 363 | Republic Energy Inc. | Decatur, TX 76234 | Oil & Gas Operator | Dec 2016 |
| 364 | Republic Energy Operating, LLC | Decatur, TX 76234 | Oil & Gas Operator | Jan 2016 |
| 365 | Rhyne, J.V. | Cisco, TX 76437 | Oil & Gas Operator | Jul 2025 |
| 366 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Jul 2025 |
| 367 | Ridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2025 |
| 368 | Rife Oil Properties Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Jul 2025 |
| 369 | Rimrock Energy, LLC | Fort Worth, TX 76147 | Oil & Gas Operator | Oct 2012 |
| 370 | Rio O & P LLC | Pasadena, TX 77504 | Oil Operator | Jul 2025 |
| 371 | Rise Petroleum Investments LLC | Tomball, TX 77377 | Oil & Gas Operator | Jul 2025 |
| 372 | RKW Operating LLC | Weatherford, TX 76085 | Gas Operator | Jul 2025 |
| 373 | Roanoke Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 1995 |
| 374 | Roberts & Hammack, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jul 2025 |
| 375 | Robinson Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Aug 2012 |
| 376 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 377 | Rockoil Energy Of Texas, Inc. | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2025 |
| 378 | Rockwall Marketing Corporation | Benbrook, TX 76126 | Oil & Gas Operator | Dec 2007 |
| 379 | Roil Mineral & Land Co. | Dallas, TX 75379 | Oil & Gas Operator | Jul 2025 |
| 380 | Rollo Resources, LLC | Granbury, TX 76049 | Gas Operator | Jul 2025 |
| 381 | Ropar Operating Co. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jul 2025 |
| 382 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 383 | Routh Operating, LLC | Dallas, TX 75204 | Oil & Gas Operator | Mar 2011 |
| 384 | Rover Petroleum Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Jul 2025 |
| 385 | Rwa, LLC | Boyd, TX 76023 | Oil & Gas Operator | Jul 2025 |
| 386 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 387 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 388 | Sage Natural Resources LLC | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 389 | Sage Oil And Gas, LLC | Graham, TX 76450 | Gas Operator | Jul 2025 |
| 390 | Salt Of The Earth Energy, LLC | Montgomery, TX 77356 | Oil & Gas Operator | Jul 2025 |
| 391 | Samco Oil & Gas Co. | Granbury, TX 76048 | Gas Operator | Feb 2002 |
| 392 | Sauder Management Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 393 | Scope Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2003 |
| 394 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 395 | Se USA Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 396 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 397 | Senkel, Wesley, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2007 |
| 398 | Serendipity Exploration, Inc. | Weatherford, TX 76087 | Gas Operator | May 1997 |
| 399 | Sha Stephens, Incorporated | Weatherford, TX 76087 | Oil & Gas Operator | Apr 2006 |
| 400 | Shamrock Minerals Corporation | Merkel, TX 79536 | Oil & Gas Operator | Nov 1998 |