| 501 | Foothills Energy LLC | Seabrook, TX 77586-3541 | Gas Operator | Feb 2013 |
| 502 | Foothills Texas, Inc. | Houston, TX 77269 | Oil & Gas Operator | Aug 2019 |
| 503 | Fora Company | Borger, TX 79007 | Oil & Gas Operator | Dec 2025 |
| 504 | Forbes Harold G | | Oil Operator | Dec 1984 |
| 505 | Forbes Producing, LLC | Corpus Christ, TX 78410 | Oil Operator | Sep 2025 |
| 506 | Forbes, C. C. Company | Alice, TX 78333 | Oil & Gas Operator | Sep 2015 |
| 507 | Forbes, Charles C. | Hebbronville, TX 78361 | Oil & Gas Operator | Jul 2011 |
| 508 | Forbes, Patrick T. | Eureka, KS 67045 | Oil Operator | Mar 2026 |
| 509 | Force 4 Energy Resources, Inc. | Austin, TX 78733 | Oil & Gas Operator | Aug 2005 |
| 510 | Force 5 Energy, LLC | Houston, TX 77090 | Oil & Gas Operator | Dec 2018 |
| 511 | Force Antrim Development Inc | | Gas Operator | Dec 1999 |
| 512 | Forcenergy Gas Exploration Inc. | Miami, FL 33129 | Oil & Gas Operator | Aug 1996 |
| 513 | Forcenergy Inc | Miami, FL 33129 | Oil & Gas Operator | Mar 2015 |
| 514 | Forcenergy Onshore Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2012 |
| 515 | Ford Chapman & Assoc | Midland, TX 79710 | Oil Operator | Sep 2000 |
| 516 | Ford Energy Corporation | Broken Arrow, OK 74011 | Oil & Gas Operator | Mar 2026 |
| 517 | Ford Gum & Machine Co., Inc. | Akron, NY 14001 | Gas Operator | Dec 2025 |
| 518 | Ford Tank Truck Service | | Oil Operator | Jan 2022 |
| 519 | Ford, Cregg | Auburn, NY 13021 | Gas Operator | Dec 2025 |
| 520 | Ford, Don H. & Assoc. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2026 |
| 521 | Ford, R. J. Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Jul 2026 |
| 522 | Fordoche Operating Company, LLC | | Oil & Gas Operator | Nov 2024 |
| 523 | Fordyce Oil & Gas | Sullivan City, TX 78595 | Oil & Gas Operator | Jul 2022 |
| 524 | Fore Oil, LLC | Manvel, TX 77578 | Oil Operator | May 2021 |
| 525 | Foree Oil Company | Terrell, TX 75160 | Oil & Gas Operator | Jul 2026 |
| 526 | Foree R L | Dallas, TX 75225 | Oil & Gas Operator | Aug 2001 |
| 527 | Foree, R. L. Trust "A" | Dallas, TX 75225 | Oil & Gas Operator | Dec 1999 |
| 528 | Foreland Operating, LLC | Royse City, TX 75189 | Oil & Gas Operator | Oct 2021 |
| 529 | Foreland Resources LLC | Lakewood, CO 80228 | Oil & Gas Operator | Oct 2025 |
| 530 | Forell Energy Company | Fullerton, CA 92838 | Oil Operator | Dec 2023 |
| 531 | Foreman Enterprises Inc | Edmond, OK 73003 | Oil & Gas Operator | Oct 2025 |
| 532 | Foreman Joy | Guymon, OK 73942-3159 | Oil & Gas Operator | Jan 2003 |
| 533 | Forest 1 Development Company | Denver, CO 80202-4966 | Oil & Gas Operator | Mar 2008 |
| 534 | Forest Gray Energy | | Oil & Gas Operator | Dec 2025 |
| 535 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 536 | Forest Oil Permian Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 537 | Forestar Group Inc | | Oil Operator | Sep 2015 |
| 538 | Forestar Oil & Gas LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2016 |
| 539 | Forestar Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2017 |
| 540 | Forexco, Inc. | Greensboro, NC 27438 | Oil & Gas Operator | Dec 2024 |
| 541 | Forge Energy Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2023 |
| 542 | Forge Energy, LLC | San Antonio, TX 78249 | Oil & Gas Operator | Apr 2019 |
| 543 | Fork Run Oil & Gas LLC | Sheffield, PA 16347-0012 | Oil & Gas Operator | Dec 2025 |
| 544 | Forman Exploration Company | | Oil & Gas Operator | Oct 1988 |
| 545 | Forman Petroleum Corporation | | Oil & Gas Operator | Aug 2001 |
| 546 | Formation Mechan | | Oil Operator | Dec 1986 |
| 547 | Formation Recovery LLC | Weatherford, TX 76087 | Oil & Gas Operator | Jul 2026 |
| 548 | Formation Resources LLC | Fort Worth, TX 76185 | Oil & Gas Operator | Jul 2026 |
| 549 | Formax Oil Company | | Oil & Gas Operator | Dec 1993 |
| 550 | Formentera Operations LLC | Austin, TX 78701 | Oil & Gas Operator | Jul 2026 |
| 551 | Formentera Opr LLC | Austin, TX 78701-4889 | Gas Operator | Apr 2026 |
| 552 | Formholtz, Allen | Lakeview, NY 14085 | Gas Operator | Dec 2025 |
| 553 | Formor Operating Inc | Tyler, TX 75701 | Oil & Gas Operator | May 2013 |
| 554 | Fornash Oil LLC | Waynesburg, OH 44688 | Oil & Gas Operator | Dec 2025 |
| 555 | Forney & McCombs | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 556 | Forney Oil Corporation | Houston, TX 77056 | Oil & Gas Operator | Jan 1998 |
| 557 | Forrest A Ward | Okmulgee, OK 74447-8891 | Oil & Gas Operator | Mar 2026 |
| 558 | Forrest Energy, LLC | Hattiesburg, MS 39401 | Oil & Gas Operator | Feb 1998 |
| 559 | Forrest Exploration & Dev, LLC | | Gas Operator | May 2003 |
| 560 | Forrest Richard E | New Bethlehem, PA 16242-2547 | Gas Operator | Dec 2019 |
| 561 | Forrest, Catherine M | | Oil & Gas Operator | Apr 2025 |
| 562 | Forrestel II, E. Peter | Akron, NY 14001 | Gas Operator | Dec 2025 |
| 563 | Forrester Oil & Gas Co. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2026 |
| 564 | Forrester, J. L. | Longview, TX 75606 | Oil & Gas Operator | Jul 2026 |
| 565 | Forsan Oil Company | Forsan, TX 79733 | Oil & Gas Operator | Jul 2008 |
| 566 | Forster Oil Co. | | Oil & Gas Operator | Dec 2016 |
| 567 | Forster, Fred Jr. | Midland, TX 79705 | Oil & Gas Operator | Aug 2008 |
| 568 | Forsythe Lawana | Wilson, OK 73463 | Oil Operator | Mar 2020 |
| 569 | Forsythe Trucking Inc | Wilson, OK 73463 | Oil & Gas Operator | Mar 2026 |
| 570 | Fort Apache Energy, Inc. | Boerne, TX 78015 | Oil & Gas Operator | Jul 2026 |
| 571 | Fort Exploration Company | FT Smith, AR 72901 | Gas Operator | May 2001 |
| 572 | Fort Operating Company | Fort Smith, AR 72923 | Gas Operator | Nov 2018 |
| 573 | Fort Worth Natural Gas, Inc. | Dallas, TX 75254 | Oil & Gas Operator | Jul 2026 |
| 574 | Fort Worth Production Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Oct 1996 |
| 575 | Fortay Inc. | Sunray, TX 79086 | Oil & Gas Operator | Jul 2026 |
| 576 | Forte Energy Corporation | Dallas, TX 75205 | Oil & Gas Operator | Dec 2010 |
| 577 | Forte Energy Corpration | Houston, TX 77024-1209 | Oil & Gas Operator | Jan 1995 |
| 578 | Fortenberry Operating Co., Inc | | Oil & Gas Operator | Nov 2003 |
| 579 | Fortenbery Drilling Co., Inc. | | Oil & Gas Operator | Oct 1979 |
| 580 | Fortenbery Operating Co Inc | | Oil & Gas Operator | May 1993 |
| 581 | Fortenbery Wade | | Oil & Gas Operator | May 1980 |
| 582 | Fortitude Exploration Co | | Oil & Gas Operator | Aug 2025 |
| 583 | Fortress Energy Corp | Pittsburgh, PA 15217-4207 | Oil & Gas Operator | Dec 2023 |
| 584 | Fortson Oil | | Oil & Gas Operator | Jan 1998 |
| 585 | Fortson Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2020 |
| 586 | Fortuna Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2014 |
| 587 | Fortuna Exploration, Inc. | Abilene, TX 79602 | Oil & Gas Operator | Jul 2026 |
| 588 | Fortuna Resources Dvlpment, LLC | Houston, TX 77055 | Oil & Gas Operator | Jul 2026 |
| 589 | Fortune Energy, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Jul 2026 |
| 590 | Fortune Gas & Oil | Shreveport, LA 71118-3457 | Oil & Gas Operator | Dec 2002 |
| 591 | Fortune Gas & Oil, Inc. | | Oil & Gas Operator | Apr 2004 |
| 592 | Fortune Natural Resources Corp. | Houston, TX 77067 | Oil & Gas Operator | Dec 2003 |
| 593 | Fortune Oil LTD | Salt Lake City, UT 84106 | Oil & Gas Operator | May 1987 |
| 594 | Fortune Operating Company | Willis, TX 77378 | Oil & Gas Operator | Jul 2026 |
| 595 | Fortune Operating, Inc. | Bowling Green, KY 42104 | Oil & Gas Operator | Jul 2026 |
| 596 | Fortune Petroleum Corporation | | Oil & Gas Operator | Dec 1994 |
| 597 | Fortune Production Co. | San Angelo, TX 76906 | Oil & Gas Operator | Dec 2008 |
| 598 | Fortune Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2026 |
| 599 | Fortune-Shelby | | Oil & Gas Operator | Mar 1989 |
| 600 | Fortune-Western | | Oil Operator | Dec 1989 |