| 301 | Harding Company | Dallas, TX 75244 | Oil & Gas Operator | Jan 2015 |
| 302 | Hardway Prod & Operating, LLC | Abilene, TX 79608 | Oil & Gas Operator | Aug 2016 |
| 303 | Harris Energy Partners Op, LLC | Fort Worth, TX 76116 | Oil Operator | Mar 2025 |
| 304 | Harvest Petroleum Inc. | Frisco, TX 75033 | Oil & Gas Operator | Mar 2025 |
| 305 | Heart Land Petroleum Corporation | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 306 | Henry, John Petroleum | Dallas, TX 75225 | Oil & Gas Operator | Dec 2001 |
| 307 | Herring, Ray | Graham, TX 76450 | Oil & Gas Operator | Jul 2014 |
| 308 | Hess, Jerry Operating Co. | Muenster, TX 76252 | Oil & Gas Operator | Mar 2025 |
| 309 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Mar 2025 |
| 310 | HGN Operating Co Inc | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 311 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 312 | Hill Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2009 |
| 313 | Hillcrest Petroleum, LLC | Midland, TX 79707 | Oil & Gas Operator | Jun 2019 |
| 314 | Hipp Oil And Gas Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Mar 2025 |
| 315 | Hodges & Hodges Productions | Anson, TX 79501 | Oil & Gas Operator | Aug 2003 |
| 316 | Hofco, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2025 |
| 317 | Holden Oil & Gas | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 318 | Hopewell Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Mar 2025 |
| 319 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 320 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 321 | Humphrey-Bashford Oil, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2010 |
| 322 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 323 | Hunt Operating, LLC | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2025 |
| 324 | Ics Energy LLC | Stamford, TX 79553 | Oil & Gas Operator | Mar 2025 |
| 325 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 326 | Integras Operating, LLC | Irving, TX 75062 | Oil & Gas Operator | Mar 2025 |
| 327 | Intergrated Petroleum Corp. | Abilene, TX 79602 | Oil & Gas Operator | Mar 2025 |
| 328 | International Western Oil Corp | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2025 |
| 329 | Interstate Explorations LLC | Houston, TX 77010 | Oil & Gas Operator | Mar 2025 |
| 330 | Ipact | Austin, TX 78734 | Oil & Gas Operator | Mar 2025 |
| 331 | Iron Bell Operating, LLC | Lubbock, TX 79423 | Oil Operator | Mar 2025 |
| 332 | Iron Horse Oil & Gas, Inc. | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 333 | J & J Trading | Abilene, TX 79608 | Oil & Gas Operator | Dec 2004 |
| 334 | J-E Production, Inc. | Midland, TX 79708 | Oil & Gas Operator | Mar 2008 |
| 335 | J. F. G. Enterprises | Artesia, NM 88210 | Oil & Gas Operator | Apr 1995 |
| 336 | J.C. Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Aug 2016 |
| 337 | J.H. Oil, Inc. (A) | Tuscola, TX 79562 | Oil & Gas Operator | Dec 2004 |
| 338 | Jacobs, C. E., Co. | Albany, TX 76430 | Oil & Gas Operator | Sep 2022 |
| 339 | Jamex, Inc. | Lewisville, TX 75067 | Oil & Gas Operator | Mar 2025 |
| 340 | Jla Resources Company | Austin, TX 78746 | Oil & Gas Operator | Mar 2025 |
| 341 | Johnson & Ernst Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2018 |
| 342 | Joint Resources Company | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2025 |
| 343 | Jones Company, LTD. | Albany, TX 76430 | Oil & Gas Operator | May 1999 |
| 344 | Jones, Jansen M. | Albany, TX 76430 | Oil & Gas Operator | Jul 2009 |
| 345 | JQL Energy, LLC | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 346 | Jrow Energy LLC | Lubbock, TX 79423 | Oil Operator | Mar 2025 |
| 347 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Mar 2025 |
| 348 | Kelt Oil & Gas, Inc. | Torrance, CA 90503 | Oil & Gas Operator | Dec 2003 |
| 349 | Killion Well Service Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2014 |
| 350 | Kilpatrick Production Company | Tye, TX 79563 | Oil & Gas Operator | Mar 2025 |
| 351 | Kimble Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2006 |
| 352 | King Oil & Resources Co | Midland, TX 79705 | Oil & Gas Operator | Mar 2025 |
| 353 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Mar 2025 |
| 354 | Kinlaw Oil Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 355 | KNK Oil & Gas | Abilene, TX 79602 | Oil & Gas Operator | Dec 1996 |
| 356 | Korman Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2001 |
| 357 | Kramer Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 358 | L-83, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 359 | L.C.S. Production Company | Abilene, TX 79608 | Oil & Gas Operator | Mar 2025 |
| 360 | La Aceite Energy, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Mar 2025 |
| 361 | Lainco Well Service, Inc. | Hamlin, TX 79520 | Oil & Gas Operator | Aug 2011 |
| 362 | Lainco, Inc. | Hamlin, TX 79520 | Oil & Gas Operator | Mar 2025 |
| 363 | Landmaster Partners, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Mar 2025 |
| 364 | Laneer Resources Company | Abilene, TX 79608 | Oil & Gas Operator | Mar 2025 |
| 365 | Lapco Oil & Gas Company | Houston, TX 77069 | Oil & Gas Operator | Oct 2015 |
| 366 | Lariat Land & Exploration, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2025 |
| 367 | Lawlis Oil Company | Hamlin, TX 79520 | Oil & Gas Operator | Mar 2025 |
| 368 | Lawrence Energy Company | Abilene, TX 79602 | Oil & Gas Operator | Mar 2025 |
| 369 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | Mar 2025 |
| 370 | Leclair Operating, L.L.C. | Abilene, TX 79602 | Oil & Gas Operator | Mar 2025 |
| 371 | Ledger Operating Corporation | Abilene, TX 79601 | Oil Operator | Mar 2025 |
| 372 | Leroy Oil Co. | Gainesville, TX 76240 | Oil & Gas Operator | Jun 2002 |
| 373 | Levee Oil LLC | Tuscola, TX 79562 | Oil Operator | Mar 2025 |
| 374 | Lime Creek Enterprises | Aztec, NM 87410 | Oil & Gas Operator | Aug 2008 |
| 375 | LKKTX 2018, LLC | Burkburnett, TX 76354 | Oil Operator | Mar 2025 |
| 376 | LMN Oil And Gas, Inc. | Luling, TX 78648 | Oil & Gas Operator | Mar 2008 |
| 377 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 378 | Lone Star Production | Lawn, TX 79530 | Oil & Gas Operator | Mar 2025 |
| 379 | Longhorn Oil Properties, Inc. | Pottsboro, TX 75076 | Oil & Gas Operator | Mar 2025 |
| 380 | Lowe, Dean | Albany, TX 76430 | Oil Operator | Mar 2025 |
| 381 | Lyco Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Jun 2015 |
| 382 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 383 | Lytle Creek Operating, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Mar 2025 |
| 384 | M & K Operating LLC | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 385 | M & M Oil & Gas Exploration Inc | Abilene, TX 79601 | Oil & Gas Operator | Mar 2008 |
| 386 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2025 |
| 387 | M-Tex Resources, Inc. | Merkel, TX 79536 | Oil & Gas Operator | Mar 2025 |
| 388 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Mar 2025 |
| 389 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 390 | Marianas Operating Co. | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 391 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Mar 2025 |
| 392 | Market Street Energy, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Mar 2025 |
| 393 | Martin, Jimmy Inc | San Angelo, TX 76904 | Oil & Gas Operator | Mar 2025 |
| 394 | Masa Energy LLC | Houston, TX 77094 | Oil & Gas Operator | Mar 2025 |
| 395 | Masters Rat Hole Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 396 | Mathis & Sons, Inc. | Rule, TX 79547 | Oil & Gas Operator | Mar 2025 |
| 397 | Maxwell, Riley G., Co. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 398 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 399 | Mayo, Paul R. | Quinlan, TX 75474 | Oil & Gas Operator | May 1999 |
| 400 | McBee Operating Company, L.L.C. | Dallas, TX 75209 | Oil & Gas Operator | Mar 2025 |