| 301 | Helmcamp, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2002 |
| 302 | Helmer Energy & Stanton Engr. | Tyler, TX 75702 | Oil & Gas Operator | Jun 1998 |
| 303 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2025 |
| 304 | Helms Oil & Gas, LLC | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 305 | Helo Energy, Inc. | Borger, TX 79008 | Oil & Gas Operator | Aug 2001 |
| 306 | Helton Petroleum | Pampa, TX 79066 | Oil & Gas Operator | Apr 2025 |
| 307 | Helton, Pat A. & Alberta | Allison, TX 79003 | Oil & Gas Operator | Apr 2025 |
| 308 | Hemco Development, LLC | Dallas, TX 75201 | Oil & Gas Operator | Nov 2020 |
| 309 | Hemco Production, L. L. C. | Dallas, TX 75201 | Oil & Gas Operator | Apr 2016 |
| 310 | Hemus, Inc. | Bellaire, TX 77401 | Oil & Gas Operator | Sep 1994 |
| 311 | Henderson & Erickson, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 312 | Henderson Natural Res, L.L.C. | Crozet, VA 22932 | Oil & Gas Operator | Apr 2025 |
| 313 | Henderson Petroleum Corp | San Angelo, TX 76906 | Oil & Gas Operator | Jul 2013 |
| 314 | Henderson, Bryan, Co. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 315 | Henderson, Peter Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2020 |
| 316 | Henderson, Sam F. | Odessa, TX 79760 | Oil & Gas Operator | Nov 2002 |
| 317 | Henderson, Sam W. | Iowa Park, TX 76367 | Oil & Gas Operator | Jun 2019 |
| 318 | Hendon WM E. Jr. Rev LVNG Trust | Everett, WA 98208 | Oil & Gas Operator | Apr 2025 |
| 319 | Hendrix, John H. Corporation | Midland, TX 79705 | Oil & Gas Operator | Sep 2018 |
| 320 | Henley Operating | Nocona, TX 76255 | Oil & Gas Operator | Apr 2025 |
| 321 | Hennan Resources, Inc. | Great Neck, NY 11021 | Gas Operator | Nov 1997 |
| 322 | Hennig Production Co., Inc. | Tyler, TX 75701 | Oil & Gas Operator | Apr 2025 |
| 323 | Henry Paul Petroleum, LLC | Pampa, TX 79066 | Oil & Gas Operator | Apr 2025 |
| 324 | Henry Petroleum Corp. | Midland, TX 79703 | Oil & Gas Operator | Mar 2001 |
| 325 | Henry Petroleum LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Apr 2025 |
| 326 | Henry Petroleum LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2008 |
| 327 | Henry Production Company, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Oct 2019 |
| 328 | Henry Resources LLC | Midland, TX 79703 | Oil & Gas Operator | Apr 2025 |
| 329 | Henry, J.R. Inc | Brenham, TX 77833 | Oil & Gas Operator | Apr 2025 |
| 330 | Henry, John Petroleum | Dallas, TX 75225 | Oil & Gas Operator | Dec 2001 |
| 331 | Henscheid, Rufus | Muenster, TX 76252 | Oil Operator | Jan 2020 |
| 332 | Henson Exploration, L.P. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 333 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 334 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 335 | Herber, Carl R. | Denton, TX 76205 | Oil & Gas Operator | Apr 2014 |
| 336 | Herbig Oil & Gas Co. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 337 | Herbig, J F | Midland, TX 79701 | Oil & Gas Operator | Mar 1998 |
| 338 | Herbst Resources, Inc. | Mandeville, LA 70448 | Oil & Gas Operator | Aug 2003 |
| 339 | Herd Producing Company, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Apr 2025 |
| 340 | Hereford, J. A. Industries, Inc. | Nacogdoches, TX 75961 | Oil & Gas Operator | Apr 2025 |
| 341 | Herencia Operating LLC | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 2025 |
| 342 | Heritage Energy Corporation | Waco, TX 76710 | Oil & Gas Operator | Sep 2004 |
| 343 | Heritage Expl. & Prod. Co., Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2000 |
| 344 | Heritage Operating Co., Inc. The | Stafford, TX 77497 | Oil & Gas Operator | May 1997 |
| 345 | Heritage Petroleum Corporation | Cleburne, TX 76033 | Oil & Gas Operator | Apr 2025 |
| 346 | Heritage Petroleum, Inc. | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2025 |
| 347 | Heritage Resources, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Feb 2014 |
| 348 | Heritage Standard Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2025 |
| 349 | Hermat Salt Water Disposal, Inc. | Corpus Chrsti, TX 78426 | Oil Operator | Aug 2012 |
| 350 | Hermes, A. J. | Lindsay, TX 76250 | Oil & Gas Operator | Mar 2018 |
| 351 | Herms, Walter | Luling, TX 78648 | Oil & Gas Operator | Sep 2002 |
| 352 | Herod Investments, Inc. | Ranger, TX 76470 | Oil & Gas Operator | Jul 1999 |
| 353 | Herod, Bill | Ranger, TX 76470 | Oil & Gas Operator | Apr 2022 |
| 354 | Herricks Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Jan 2010 |
| 355 | Herring, Casey Oil Co. | Santa Anna, TX 76878 | Oil & Gas Operator | Nov 2008 |
| 356 | Herring, D Oil & Gas Co. | Santa Anna, TX 76878 | Oil & Gas Operator | Apr 2025 |
| 357 | Herring, Ray | Graham, TX 76450 | Oil & Gas Operator | Jul 2014 |
| 358 | Herrmann Energy | Amarillo, TX 79159 | Oil & Gas Operator | May 2015 |
| 359 | Herrmann, J.B. | Amarillo, TX 79159 | Oil & Gas Operator | Aug 2019 |
| 360 | Herrmann, S. W. Oil & Gas | Amarillo, TX 79159 | Oil & Gas Operator | Apr 2025 |
| 361 | Herschap Bros. | Bruni, TX 78344 | Oil & Gas Operator | Apr 2025 |
| 362 | Hershey Oil Corporation | Seminole, TX 79360 | Oil & Gas Operator | Jul 1992 |
| 363 | Herv Oil, LLC | Oklahoma City, OK 73116 | Oil Operator | Jan 2025 |
| 364 | Herzfeld Fabricators Inc | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2017 |
| 365 | Hess Bros. DRLG. Co. | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2008 |
| 366 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 367 | Hess Production | Quitaque, TX 79255 | Oil & Gas Operator | Apr 2025 |
| 368 | Hess Seminole Assets LLC | Seminole, TX 79360 | Oil & Gas Operator | Aug 2017 |
| 369 | Hess, Jerry Operating Co. | Muenster, TX 76252 | Oil & Gas Operator | Apr 2025 |
| 370 | Hewitt, Alan P. | Midland, TX 79702 | Oil & Gas Operator | Aug 1997 |
| 371 | Hewitt, Robert J. | Victoria, TX 77901 | Oil & Gas Operator | Jun 2004 |
| 372 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Apr 2025 |
| 373 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 374 | Heydrick Petroleum Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2025 |
| 375 | Hez Petroleum Company | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 376 | HG Operating LLC | Plano, TX 75026 | Oil & Gas Operator | Apr 2025 |
| 377 | HGB Oil Company | Denver, CO 80224 | Oil Operator | Mar 2006 |
| 378 | Hgi Corporation | Nada, TX 77460 | Oil & Gas Operator | Apr 2016 |
| 379 | HGN Operating Co Inc | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 380 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 381 | HH&F Partners | Katy, TX 77450 | Oil & Gas Operator | Sep 2019 |
| 382 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Apr 2025 |
| 383 | Hi Plains Hydrocarbons, Inc. | Sunray, TX 79086 | Oil & Gas Operator | Oct 2002 |
| 384 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Apr 2025 |
| 385 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 386 | Hibernia Resources IV, LLC | Houston, TX 77056 | Oil & Gas Operator | Apr 2025 |
| 387 | Hibernia Resources, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2014 |
| 388 | Hickman & Ickert | Olney, TX 76374 | Oil & Gas Operator | Feb 2002 |
| 389 | Hickman-Jordan-Halligan Ranches | Blackwell, TX 79506 | Oil & Gas Operator | Feb 1998 |
| 390 | Hickory Petroleum Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2013 |
| 391 | Hickox Oil Texas Company, Inc. | Mobile, AL 36689 | Oil & Gas Operator | Feb 1996 |
| 392 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Dec 2024 |
| 393 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 394 | Hidalgo Oil & Exploration Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Apr 2025 |
| 395 | Higginbotham, O. V. | Cedar Park, TX 78613 | Oil & Gas Operator | Jul 1996 |
| 396 | High Bluff Operating, LLC | Littleton, CO 80161 | Oil & Gas Operator | May 2018 |
| 397 | High Chapparal Oil Company | Plntersville, TX 77363 | Oil & Gas Operator | Aug 2003 |
| 398 | High Desert Resources, L.L.C. | Midland, TX 79704 | Oil Operator | Apr 2025 |
| 399 | High Island Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 400 | High Island Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2017 |