| 301 | Hadson Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 1994 |
| 302 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 303 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2026 |
| 304 | Halvey Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 305 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Sep 2026 |
| 306 | Hannathon Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 307 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 308 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 309 | Hat Oil & Gas, Inc. | Slaton, TX 79364 | Oil & Gas Operator | Feb 2002 |
| 310 | HCM | Dallas, TX 75206 | Oil & Gas Operator | Mar 2015 |
| 311 | Hec Petroleum, Inc | Midland, TX 79705 | Oil & Gas Operator | Mar 2006 |
| 312 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 313 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 314 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 315 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 316 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Sep 2026 |
| 317 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 318 | Hess Seminole Assets LLC | Seminole, TX 79360 | Oil & Gas Operator | Aug 2017 |
| 319 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 320 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Sep 2026 |
| 321 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 322 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Sep 2026 |
| 323 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 324 | Hillin Simon/Prime Expl., L.C. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 325 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 326 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 327 | Hog Partnership LP | Dallas, TX 75235 | Gas Operator | Jul 2026 |
| 328 | Home-Stake Oil & Gas Company | Plano, TX 75093 | Oil & Gas Operator | May 2026 |
| 329 | Home-Stake Royalty Corp., The | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2014 |
| 330 | Hopkins, T. M. Operating Co. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 331 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 332 | Houghton Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Mar 2009 |
| 333 | Houston Energy Operating, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2020 |
| 334 | Houston Energy, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2014 |
| 335 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 336 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 337 | Hub-Cap Oil Company | Arlington, TX 76016 | Oil & Gas Operator | Dec 2013 |
| 338 | Hubcap Oil, LLC | Boerne, TX 78015 | Oil Operator | Sep 2026 |
| 339 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Sep 2026 |
| 340 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 341 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 342 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 343 | HW Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2026 |
| 344 | Ica Energy Operating, L.L.C. | Odessa, TX 79760 | Oil & Gas Operator | Sep 2026 |
| 345 | Imperial Oil Company | Houston, TX 77073 | Oil & Gas Operator | Oct 2004 |
| 346 | Incline Energy | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 347 | Inject Technologies Inc. | Andrews, TX 79714 | Oil Operator | Sep 2026 |
| 348 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 349 | J C Petroleum Inc | Chickasha, OK 73023-1433 | Oil & Gas Operator | Dec 2013 |
| 350 | Jasmar Oil Co. | Levelland, TX 79336 | Oil & Gas Operator | Mar 2008 |
| 351 | JD Oil Company | Longview, TX 75605 | Oil & Gas Operator | Sep 2014 |
| 352 | Jetta Operating Company, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2026 |
| 353 | JM Cox Resources LP | Midland, TX 79702 | Oil & Gas Operator | Apr 2019 |
| 354 | Johnson And Price | Midland, TX 79702 | Oil & Gas Operator | Dec 1995 |
| 355 | Joint Resources Company | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2026 |
| 356 | Jones, L. E. Operating, Inc. | Duncan, OK 73534 | Oil & Gas Operator | Sep 2026 |
| 357 | Just Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Sep 2026 |
| 358 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Sep 2026 |
| 359 | Kemper Operating Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2015 |
| 360 | Kendrick Oil And Gas Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2026 |
| 361 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 362 | Keystone Petroleum GP LLC | Irving, TX 75039 | Oil & Gas Operator | May 2012 |
| 363 | Kimball Production Co. | Houston, TX 77042 | Oil & Gas Operator | Jul 2002 |
| 364 | Kimbell Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2026 |
| 365 | Kimbrough Engineering Co, LLC | New Braunfels, TX 78132 | Oil & Gas Operator | Dec 2014 |
| 366 | Kimsey, Roy E., Jr. | Midland, TX 79701 | Oil & Gas Operator | May 2018 |
| 367 | Kinder Morgan Production Co LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 368 | Kindred Petroleum Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 369 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Sep 2026 |
| 370 | King Ranch Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 1997 |
| 371 | Kinney Incorporated | Andrews, TX 79714 | Oil & Gas Operator | Sep 2026 |
| 372 | Klabzuba Royalty Company | Prague, OK 74864-0567 | Oil & Gas Operator | Dec 2019 |
| 373 | Knox Industries, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Sep 2026 |
| 374 | L.C.S. Production Company | Abilene, TX 79608 | Oil & Gas Operator | Sep 2026 |
| 375 | L7 Energy LLC | Wichita Falls, TX 76308 | Oil Operator | Sep 2026 |
| 376 | La VIda Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1993 |
| 377 | Lackey, William H. Oil And Gas | Shawnee, OK 74804 | Oil & Gas Operator | Feb 2024 |
| 378 | Ladd Oil & Gas Corporation | Midland, TX 79711 | Oil & Gas Operator | Dec 2021 |
| 379 | Ladd Operating Company | Midland, TX 79711 | Oil & Gas Operator | Mar 2008 |
| 380 | Laguna Petroleum Corporation | Houston, TX 77046 | Oil & Gas Operator | Sep 2026 |
| 381 | Lance Leasing | Odessa, TX 79765 | Oil Operator | Sep 2026 |
| 382 | Lanexco, Inc. | Sealy, TX 77474 | Oil & Gas Operator | Sep 2026 |
| 383 | Lario Oil & Gas Company | Denver, CO 80206 | Oil & Gas Operator | Sep 2026 |
| 384 | Lasso Oil & Gas LLC | Dallas, TX 75360 | Oil & Gas Operator | Jul 2022 |
| 385 | Latigo Petroleum Texas, LP | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 386 | Ledger Operating Corporation | Abilene, TX 79604 | Oil Operator | Sep 2026 |
| 387 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Sep 2026 |
| 388 | Libertad Operating LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 389 | Limark Corporation | Midland, TX 79702 | Oil & Gas Operator | Dec 2003 |
| 390 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 391 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Jun 2025 |
| 392 | Lion Production, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2006 |
| 393 | Little, Quintin Company,Inc.,The | Ardmore, OK 73402 | Oil & Gas Operator | Sep 2026 |
| 394 | Lobo Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 395 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 396 | Lone Star Oil & Gas | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 397 | Los Hijos De Sanchez J LLC | Beeville, TX 78102 | Oil Operator | Sep 2026 |
| 398 | Lovelady, I. W. | Albuquerque, NM 87111 | Oil & Gas Operator | Jan 1996 |
| 399 | Low-End Oil LLC | Austin, TX 78748 | Oil Operator | Sep 2026 |
| 400 | LTS Oil & Gas | Lubbock, TX 79424 | Oil & Gas Operator | Sep 2026 |