| 401 | High Sierra Operating, LTD. | Canyon Lake, TX 78133 | Oil & Gas Operator | Mar 2008 |
| 402 | High Sky Oil & Gas | Midland, TX 79705 | Oil & Gas Operator | Jun 2008 |
| 403 | High Sky Partners LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2015 |
| 404 | Higher Standard Oil Company,Inc. | Frisco, TX 75034 | Oil Operator | Jul 2025 |
| 405 | Highground, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Jul 2025 |
| 406 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 407 | Highmark Energy Operating, LLC | Dallas, TX 75222 | Oil & Gas Operator | Jul 2025 |
| 408 | Highmount Expl & Prod Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2014 |
| 409 | Highmount Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2014 |
| 410 | Highpeak Energy Holdings, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 411 | Hightower Exploration | Kilgore, TX 75662 | Oil & Gas Operator | Jul 2025 |
| 412 | Hilbers Oil & Gas | Archer City, TX 76351 | Oil & Gas Operator | Oct 2002 |
| 413 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Jul 2025 |
| 414 | Hill Operating LLC | Mineral Wells, TX 76068 | Oil & Gas Operator | Nov 2023 |
| 415 | Hill Production Co Inc-Wisconsin | Humble, TX 77347 | Oil & Gas Operator | Jun 1993 |
| 416 | Hill Production Company | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2009 |
| 417 | Hill, A G | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 418 | Hill, Albert, Trust | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 419 | Hill, Bill | Kilgore, TX 75663 | Oil Operator | Mar 2014 |
| 420 | Hill, Charles Drilling, Inc. | Grand Prairie, TX 75052 | Oil & Gas Operator | Jul 2025 |
| 421 | Hill, Hub, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jan 1994 |
| 422 | Hill, R.M. Operating Inc. | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 423 | Hill, T. R. | Graham, TX 76450 | Oil & Gas Operator | Apr 1995 |
| 424 | Hill-Lake Gas Storage, L.P. | Houston, TX 77057 | Oil & Gas Operator | Aug 2010 |
| 425 | Hill-Lake Gas Storage, LLC | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2025 |
| 426 | Hillcrest Petroleum, LLC | Midland, TX 79707 | Oil & Gas Operator | Jun 2019 |
| 427 | Hilliard Oil | Bronte, TX 76933 | Oil & Gas Operator | Mar 2008 |
| 428 | Hilliard Oil & Gas Inc | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 429 | Hilliard Petroleum Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2009 |
| 430 | Hillin Prod. Co. | Odessa, TX 79760 | Oil & Gas Operator | Apr 2002 |
| 431 | Hillin Simon/Prime Expl., L.C. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 432 | Hillin, T. A. | Kerrville, TX 78028 | Oil & Gas Operator | Aug 2020 |
| 433 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 434 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 435 | Hilltex Operating Company, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jul 2021 |
| 436 | Hilltop Petroleum LLC | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2025 |
| 437 | Hillwood Energy Texas, L.P. | Fort Worth, TX 76177 | Gas Operator | Jan 2010 |
| 438 | Hillwood O & G Operating Co LP | Fort Worth, TX 76102 | Gas Operator | Jul 2025 |
| 439 | Hilty Interests, Inc. | Kerrville, TX 78028 | Oil & Gas Operator | Jun 1989 |
| 440 | Hindman, E. C. Jr. Partnership | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2008 |
| 441 | Hinds Petroleum, LLC | Houston, TX 77263 | Oil Operator | Jul 2025 |
| 442 | Hinds Petroleum, LP | Houston, TX 77263 | Oil Operator | Feb 2017 |
| 443 | Hines, Ralph, Jr. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2002 |
| 444 | Hinkle Engineering, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2016 |
| 445 | Hinkle, Howard L. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jul 2025 |
| 446 | Hinton Production Company | MT Pleasant, TX 75455 | Oil & Gas Operator | Aug 1995 |
| 447 | Hinton, W. B. | MT Pleasant, TX 75455 | Oil & Gas Operator | Jul 1993 |
| 448 | Hipp Oil And Gas Inc. | Big Spring, TX 79720 | Oil & Gas Operator | Jul 2025 |
| 449 | Hitex Resources, LP | Houston, TX 77265 | Oil & Gas Operator | Jul 2025 |
| 450 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 451 | HMH Operators, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 452 | HMT Genesis Petroleum Corp. | Fort Worth, TX 76116 | Oil & Gas Operator | Nov 2008 |
| 453 | HMX Investments, Inc. | Katy, TX 77494 | Oil & Gas Operator | Apr 2025 |
| 454 | HNG Storage Company | Houston, TX 77042 | Oil & Gas Operator | Mar 2002 |
| 455 | Hobbs Energy Corporation | San Angelo, TX 76904 | Oil & Gas Operator | Mar 2008 |
| 456 | Hoc Operating Co., Inc. | Houston, TX 77056 | Oil & Gas Operator | Nov 1999 |
| 457 | Hoco Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 458 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | May 2025 |
| 459 | Hodgden, Jack D. | Enid, OK 73702 | Oil & Gas Operator | Apr 2000 |
| 460 | Hodge T F | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2007 |
| 461 | Hodges & Hodges Productions | Anson, TX 79501 | Oil & Gas Operator | Aug 2003 |
| 462 | Hodges & Rister | Abilene, TX 79603 | Oil & Gas Operator | Apr 2016 |
| 463 | Hodges, James Aaron | Fort Worth, TX 76179 | Oil & Gas Operator | Jul 2025 |
| 464 | Hodges, Thomas | Alvord, TX 76225 | Oil & Gas Operator | Oct 2002 |
| 465 | Hoell Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2025 |
| 466 | Hoelscher, Weldon | San Angelo, TX 76904 | Oil & Gas Operator | Aug 2003 |
| 467 | Hoermann, S. E. | Seguin, TX 78155 | Oil & Gas Operator | Jul 2025 |
| 468 | Hofco, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2025 |
| 469 | Hoffmann Oil Company | Eastland, TX 76448 | Oil & Gas Operator | Jul 2025 |
| 470 | Hog Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 471 | Hogan, Wayne Oil Co. | Albany, TX 76430 | Oil & Gas Operator | Jun 2006 |
| 472 | Hoggard, Kenneth | Loving, TX 76460 | Oil & Gas Operator | Jul 2025 |
| 473 | Holbein & Wright Resources Inc. | Bandera, TX 78003 | Oil & Gas Operator | Jul 2025 |
| 474 | Holco Oil & Gas | Borger, TX 79008 | Oil & Gas Operator | Jul 2025 |
| 475 | Holcomb Company, The | Freer, TX 78357 | Oil & Gas Operator | Aug 1996 |
| 476 | Holcomb Enterprises | Clyde, TX 79510 | Oil & Gas Operator | Aug 2003 |
| 477 | Holden Energy Corporation | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2015 |
| 478 | Holden Oil & Gas | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 479 | Holifield Oil Company | Giddings, TX 78942 | Oil & Gas Operator | Mar 2009 |
| 480 | Holland Oil & Gas | Brookesmith, TX 76827 | Oil & Gas Operator | Dec 2010 |
| 481 | Holland Oil Co. | Petrolia, TX 76377 | Oil Operator | Aug 2010 |
| 482 | Holland, W. M. | Petrolia, TX 76377 | Oil & Gas Operator | Jul 2009 |
| 483 | Hollandsworth & Travis | Longview, TX 75606 | Oil & Gas Operator | Mar 2001 |
| 484 | Holler Oil Co. | San Angelo, TX 76906 | Oil & Gas Operator | Aug 2003 |
| 485 | Holley Oil Company, LLC | Chappell Hill, TX 77426 | Oil & Gas Operator | Jul 2025 |
| 486 | Holley Operating, L. L. C. | Abilene, TX 79601 | Oil Operator | Jul 2025 |
| 487 | Holli-Tex Supply Co. | Holliday, TX 76366 | Oil & Gas Operator | May 2018 |
| 488 | Holliday CSG Corp. | Holliday, TX 76366 | Oil & Gas Operator | Jul 2025 |
| 489 | Holliday Drilling, Inc. | Stephenville, TX 76401 | Oil & Gas Operator | Dec 2020 |
| 490 | Hollimon Oil Corporation | Castroville, TX 78009 | Oil & Gas Operator | Nov 2016 |
| 491 | Holloway Oil Company | Austin, TX 78764 | Oil & Gas Operator | Feb 2004 |
| 492 | Hollub Production Company | Seguin, TX 78156 | Oil & Gas Operator | Jul 2000 |
| 493 | Hollub, Lambert Drilling Company | Seguin, TX 78155 | Oil & Gas Operator | Jul 2025 |
| 494 | Holly Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2008 |
| 495 | Holmac Oil Company | Hobbs, NM 88240 | Oil & Gas Operator | May 1996 |
| 496 | Holmes Exploration, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2015 |
| 497 | Holson Well Service | Albany, TX 76430 | Oil & Gas Operator | Jul 2025 |
| 498 | Holt Brothers | Gruver, TX 79040 | Gas Operator | Jul 2025 |
| 499 | Holt Oil And Cattle LLC | Bedias, TX 77831 | Oil & Gas Operator | Jul 2025 |
| 500 | Hombre Oil Co., LTD. | Tyler, TX 75713 | Oil & Gas Operator | Apr 2021 |