| 501 | Hoover Petroleum Company, LLC | Midland, TX 79701 | Oil Operator | Apr 2024 |
| 502 | Hopco Operating, Inc. | Stafford, TX 77497 | Oil & Gas Operator | Dec 2016 |
| 503 | Hope Energy, L.L.C. | Snyder, TX 79549 | Oil & Gas Operator | Apr 2024 |
| 504 | Hope Production, Inc. | Edinburg, TX 78540 | Oil & Gas Operator | Jan 2000 |
| 505 | Hopewell Operating, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2024 |
| 506 | Hopkins Engineering, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 1996 |
| 507 | Hopkins, T. M. Operating Co. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 508 | Hopper, Harlan | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 509 | Hopper, Thornton Co. | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 510 | Horadam, Henry L. | Victoria, TX 77905 | Oil & Gas Operator | Oct 2008 |
| 511 | Horansky Burrell Revocable Trust | Wichita Falls, TX 76308 | Oil Operator | Apr 2024 |
| 512 | Horany, Ray & Ernest | Olney, TX 76374 | Oil & Gas Operator | May 2002 |
| 513 | Horizon Energy | Vergas, MN 56587 | Oil & Gas Operator | Apr 2024 |
| 514 | Horizon Exploration Company | Houston, TX 77019 | Oil & Gas Operator | Aug 2002 |
| 515 | Horizon Exploration Services | El Paso, TX 79922 | Oil Operator | Apr 2024 |
| 516 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Jan 2024 |
| 517 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 518 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 519 | Horizon Prod. And Operating, LLC | Houston, TX 77019 | Oil & Gas Operator | Apr 2024 |
| 520 | Horizon Ridge Oil Company | Austin, TX 78738 | Oil Operator | Apr 2024 |
| 521 | Horizon Well Services, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 522 | Horn Energy | Eastland, TX 76448 | Oil & Gas Operator | Apr 2024 |
| 523 | Horn, W. J. | Graham, TX 76450 | Oil & Gas Operator | Oct 2004 |
| 524 | Horne & Moore Oil Co. | Holliday, TX 76366 | Oil & Gas Operator | Feb 2001 |
| 525 | Horseshoe Production, LLC | Bryson, TX 76427 | Oil Operator | Apr 2024 |
| 526 | Horst Energy LLC | Fort Worth, TX 76124 | Oil & Gas Operator | Jun 2019 |
| 527 | Hosford Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 1994 |
| 528 | Hou-Tex, Inc. | Houston, TX 77224 | Oil & Gas Operator | Jun 2001 |
| 529 | Houchin, O. E. Inc. | Olney, IL 62450 | Oil & Gas Operator | Feb 1997 |
| 530 | Houghton Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Mar 2009 |
| 531 | Houston Energy Operating, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jul 2020 |
| 532 | Houston Energy, L.P. | Houston, TX 77002 | Oil & Gas Operator | Jan 2014 |
| 533 | Houston Gulf Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 2024 |
| 534 | Houston Hydrocarbons, Inc. (A) | Houston, TX 77042 | Oil & Gas Operator | Sep 2004 |
| 535 | Houston Oil & Gas Company, Inc. | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 536 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 537 | Houston Oil Prod Enterprises,Inc | Houston, TX 77006 | Oil & Gas Operator | Apr 2024 |
| 538 | Houston Operating, Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2024 |
| 539 | Houston Petroleum Company | Houston, TX 77027 | Oil & Gas Operator | Apr 2024 |
| 540 | Houston Resources Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2003 |
| 541 | Houtchens, D. D. | Gainesville, TX 76240 | Oil & Gas Operator | Apr 2024 |
| 542 | Houtchens, DD & Anna D LVNG TRST | Garland, TX 75043 | Oil Operator | Apr 2024 |
| 543 | Hovgard & Fitzgerald | Abilene, TX 79608 | Oil & Gas Operator | Mar 1996 |
| 544 | Howard Exploration, Inc. | Houston, TX 77069 | Oil & Gas Operator | Apr 2024 |
| 545 | Howard Operating Co. | Nocona, TX 76255 | Oil & Gas Operator | Apr 2024 |
| 546 | Howard, Anthony E. F. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2001 |
| 547 | Howard, Douglas J. | Houston, TX 77070 | Oil & Gas Operator | Mar 2008 |
| 548 | Howell & Sandlin, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Jan 2001 |
| 549 | Howell Crane & Rigging, Inc. | San Antonio, TX 78220 | Oil Operator | Apr 2024 |
| 550 | Howell Drilling, Inc. | San Antonio, TX 78230 | Oil & Gas Operator | Aug 2003 |
| 551 | Howell Oil & Gas, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Oct 2019 |
| 552 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 553 | Howell, VIrginia C. Estate Of | Breckenridge, TX 76424 | Gas Operator | Apr 2024 |
| 554 | Howitzer Operating, LLC | Farmers BRNCH, TX 75234 | Oil Operator | Apr 2024 |
| 555 | Howle Operating Account, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 1999 |
| 556 | Howle, A.G. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2011 |
| 557 | HPC Energy LLC | Midland, TX 79703 | Oil & Gas Operator | Aug 2013 |
| 558 | HPC Operating, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Mar 2008 |
| 559 | HPPC, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2023 |
| 560 | HR Petroleum | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Apr 1998 |
| 561 | HRB Oil | Houston, TX 77042 | Oil & Gas Operator | Oct 1998 |
| 562 | HRB Operating Company Inc | Bridgeport, TX 76426 | Oil & Gas Operator | Apr 2024 |
| 563 | Hrbacek Oil Corp. | La Grange, TX 78945 | Oil & Gas Operator | Feb 2004 |
| 564 | HRF Exploration & Production LLC | Gaylord, MI 49734-0160 | Gas Operator | Apr 2024 |
| 565 | HRF Exploration & Production,Inc | Denver, CO 80237 | Oil & Gas Operator | Mar 2009 |
| 566 | HRH Energy Group Incorporated | Carrollton, TX 75006 | Oil & Gas Operator | Nov 2009 |
| 567 | Hronek, Kenneth | Caldwell, TX 77836 | Oil & Gas Operator | Apr 2024 |
| 568 | Hrubetz Oil Co. | Dallas, TX 75225 | Oil Operator | Sep 1986 |
| 569 | Hrubetz Operating Company | Dallas, TX 75225 | Oil & Gas Operator | Feb 1999 |
| 570 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 571 | Hub-Cap Oil Company | Arlington, TX 76016 | Oil & Gas Operator | Dec 2013 |
| 572 | Hubbard Operating | Ozona, TX 76943 | Gas Operator | Apr 2024 |
| 573 | Hubcap Oil, LLC | Arlington, TX 76016 | Oil Operator | Apr 2024 |
| 574 | Hubco Exploration Inc. | Houston, TX 77073 | Oil & Gas Operator | Sep 2002 |
| 575 | Huber Energy L.P. | Houston, TX 77079 | Oil & Gas Operator | Feb 2007 |
| 576 | Huber Energy Panhandle LP | Houston, TX 77079 | Oil & Gas Operator | Oct 2005 |
| 577 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Apr 2024 |
| 578 | Hudgens Operating Co., Inc. | Abilene, TX 79603 | Oil & Gas Operator | Jul 1995 |
| 579 | Hudson, Comer Oil & Gas | Cisco, TX 76437 | Oil & Gas Operator | Jan 2003 |
| 580 | Huff Minerals, LTD. | Amarillo, TX 79101 | Gas Operator | Apr 2024 |
| 581 | Huff, Jack | Midland, TX 79710 | Oil & Gas Operator | Dec 2004 |
| 582 | Huffman, H. L., LTD. | Fort Worth, TX 76113 | Oil & Gas Operator | Sep 1994 |
| 583 | Hufo Production Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2002 |
| 584 | Huggs Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2003 |
| 585 | Hughes & Patterson Oper. Corp. | Albany, TX 76430 | Oil & Gas Operator | Apr 2024 |
| 586 | Hughes & Shawver | Olney, TX 76374 | Oil & Gas Operator | Aug 1996 |
| 587 | Hughes Legacy LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2022 |
| 588 | Hughes Oil Company Inc | Odessa, TX 79765 | Oil & Gas Operator | Feb 2004 |
| 589 | Hughes Supplies, Inc. | Greenwood, LA 71033 | Oil & Gas Operator | Jul 2019 |
| 590 | Hughes, Bill Drilling, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 591 | Hughes, Bob Oil Company | San Angelo, TX 76901 | Oil & Gas Operator | Jul 2011 |
| 592 | Hughes, Dan A. Company | Beeville, TX 78104 | Oil & Gas Operator | May 2006 |
| 593 | Hughes, Dan A. Company, L.P. | Beeville, TX 78104 | Oil & Gas Operator | Apr 2024 |
| 594 | Hughey, Gaylord T. SR. Oper. Co. | Tyler, TX 75711 | Oil & Gas Operator | Feb 1998 |
| 595 | Hughey, W. R., Operating Co. | Tyler, TX 75711 | Oil & Gas Operator | Feb 2005 |
| 596 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 597 | Hugoton Operating Company, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 598 | Hugus Investment Company, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Apr 2024 |
| 599 | Hulen Operating Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2024 |
| 600 | Hull Oil Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2021 |