| 601 | West Tuleta Operating Corp. | Tuleta, TX 78162 | Oil & Gas Operator | May 2019 |
| 602 | West VIrginia Land Resources, Inc. | | Oil & Gas Operator | Dec 2021 |
| 603 | West X, Inc. | Hays, KS 67601 | Oil Operator | Aug 1997 |
| 604 | West,Gordon T.Jr. & Rugeley,Stan | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2019 |
| 605 | West-States Energy, Inc. | Rimrock, AZ 86335 | Oil Operator | Oct 2025 |
| 606 | Westall Oil & Gas Co. | | Oil & Gas Operator | May 1982 |
| 607 | Westall-Mask | Roswell, NM 88201 | Oil & Gas Operator | Dec 1994 |
| 608 | Westamerica Corporation | Dewey, OK 74029-0040 | Oil & Gas Operator | Aug 1999 |
| 609 | Westar Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 610 | Westar Oil & Minerals | | Oil Operator | Feb 1999 |
| 611 | Westbrook Oil & Gas Co. Inc. | Gainesville, TX 76240 | Oil & Gas Operator | Oct 2025 |
| 612 | Westbrook Oil Corp | Jal, NM 88252 | Oil & Gas Operator | May 2018 |
| 613 | Westburne Petroleum Inc | | Oil Operator | Jun 1990 |
| 614 | Westco Oil Company | Ozona, TX 76943 | Oil & Gas Operator | Oct 2025 |
| 615 | Westech Energy C | | Oil & Gas Operator | Dec 1996 |
| 616 | Westech Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Mar 2011 |
| 617 | Westek Resources, Inc. | | Oil & Gas Operator | Jan 2004 |
| 618 | Westend Operating LLC | Collinsville, OK 74021 | Oil Operator | Jul 2025 |
| 619 | Westerly Exploration, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 2025 |
| 620 | Western Alliance Petroleum | | Oil & Gas Operator | Dec 1987 |
| 621 | Western American Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2024 |
| 622 | Western Avenue Properties | | Oil & Gas Operator | Dec 1993 |
| 623 | Western Chief Oil & Gas Company | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 624 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 625 | Western Continental Operating Company | | Oil & Gas Operator | Dec 2007 |
| 626 | Western Discovery USA Inc. | | Oil & Gas Operator | Jan 2018 |
| 627 | Western Disposal Systems, Inc. | Corrales, NM 87048 | Oil Operator | Oct 2025 |
| 628 | Western Division Investments Inc | Enid, OK 73701 | Oil & Gas Operator | Jul 2021 |
| 629 | Western DRLG. Co. | Longview, TX 75604 | Oil & Gas Operator | Nov 1996 |
| 630 | Western Energy Group, LLC | Leander, TX 78641 | Oil & Gas Operator | Oct 2025 |
| 631 | Western Energy Management, Inc. | Austin, TX 78716 | Oil & Gas Operator | Aug 1997 |
| 632 | Western Engineering, Inc. | | Oil Operator | Dec 1998 |
| 633 | Western Exploration, Inc. | | Oil Operator | May 1984 |
| 634 | Western Farmers Electric Coop | Anadarko, OK 73005-0429 | Oil & Gas Operator | Apr 2012 |
| 635 | Western Field Exploration, Inc. | Dilley, TX 78017 | Oil & Gas Operator | Oct 2025 |
| 636 | Western Frontier Adventure, LLC | Easton, KS 66020 | Oil Operator | Dec 2019 |
| 637 | Western Fuel & S | | Oil Operator | Oct 1987 |
| 638 | Western Gas Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 639 | Western Gas Resources Storage | Denver, CO 80234 | Oil & Gas Operator | Jun 1999 |
| 640 | Western Gas Resources-Sand Wash Inc | | Oil & Gas Operator | Feb 2008 |
| 641 | Western Global Oil, Inc | Deerfld Beach, FL 33442 | Oil Operator | Oct 2025 |
| 642 | Western Gulf Oil & Gas Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jul 2000 |
| 643 | Western Gulf Oil & Gas, LLC | Bishop, TX 78343 | Oil & Gas Operator | Oct 2025 |
| 644 | Western Hemisphere Group | Buffalo, NY 14218 | Oil & Gas Operator | Dec 1993 |
| 645 | Western Interior Energy Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2020 |
| 646 | Western Interior Oil & Gas Corp | Casper, WY 82602 | Oil & Gas Operator | May 2015 |
| 647 | Western Kansas E | | Oil Operator | Aug 1993 |
| 648 | Western Meadowlark Resources LLC | Denver, CO 80206 | Oil & Gas Operator | Jun 2025 |
| 649 | Western Metals Corporation | | Oil & Gas Operator | Aug 2025 |
| 650 | Western Mountain Resources LLC | Cogan Station, PA 17728 | Oil & Gas Operator | Jun 2025 |
| 651 | Western Natl Resource Expl LLC | Oklahoma City, OK 73154-0755 | Oil & Gas Operator | Mar 2015 |
| 652 | Western Natural Gas | | Oil & Gas Operator | Aug 1974 |
| 653 | Western Natural Gas Company | Shelby, MT 59474 | Oil & Gas Operator | Jun 2025 |
| 654 | Western Natural Resources Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2015 |
| 655 | Western New York Drilling Associates 1, L.P. | Buffalo, NY 14201 | Oil & Gas Operator | Dec 2024 |
| 656 | Western Oil & Gas Development Co. | Robinson, IL 62454 | Oil Operator | Jun 2000 |
| 657 | Western Oil & Minerals LTD | Farmington, NM 874991228 | Oil & Gas Operator | Aug 2025 |
| 658 | Western Oil And Gas Development Corp | Oklahoma City, OK 73103-3735 | Oil & Gas Operator | Jul 2025 |
| 659 | Western Oil Comp | | Oil Operator | Aug 1989 |
| 660 | Western Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2014 |
| 661 | Western Oil Independent LLC | | Oil & Gas Operator | Dec 2016 |
| 662 | Western Oil Producers Inc | Roswell, NM 88202 | Oil & Gas Operator | Jul 2005 |
| 663 | Western Oil Refining Company | Kemmerrer, WY 83101 | Oil & Gas Operator | Dec 1994 |
| 664 | Western Operating Company | Denver, CO 80204 | Oil & Gas Operator | Jul 2025 |
| 665 | Western Pacific Farms, Inc. | Copeland, KS 67837 | Oil & Gas Operator | Apr 2020 |
| 666 | Western Petroleum Company Inc | Tulsa, OK 74170-2676 | Oil & Gas Operator | Apr 2020 |
| 667 | Western Petroleum Resources, Inc | Dallas, TX 75219 | Oil & Gas Operator | May 2021 |
| 668 | Western Plains Resources LLC | Garden City, KS 67846 | Oil & Gas Operator | Jun 2025 |
| 669 | Western Pride Resources, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Jan 2011 |
| 670 | Western Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 671 | Western Products Corporation | Fairview, OK 73737 | Oil & Gas Operator | Nov 2004 |
| 672 | Western Properti | | Oil Operator | Oct 1987 |
| 673 | Western Reserve Exp | Perry, OH 44081 | Oil & Gas Operator | Dec 2003 |
| 674 | Western Reserves Corporation | Abilene, TX 79608 | Oil & Gas Operator | Jan 2008 |
| 675 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 676 | Western Reserves Oil Co Inc And Sullivan And Co | | Oil & Gas Operator | Jul 2001 |
| 677 | Western Resources And Clean Energy, LLC | Manti, UT 84642 | Oil & Gas Operator | Sep 2025 |
| 678 | Western Resources, Inc. | | Oil Operator | Jun 1994 |
| 679 | Western Resources{Wva}Inc | Chantilly, VA 22022 | Oil & Gas Operator | Dec 1994 |
| 680 | Western Sky Oil & Gas | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 681 | Western States International Inc. | | Oil & Gas Operator | Jul 2025 |
| 682 | Western Tank Trucks Inc | Hennessey, OK 73742 | Oil Operator | Jul 2011 |
| 683 | Westfall-Gooden Reserves LLC | Oklahoma City, OK 73106 | Oil & Gas Operator | Jun 2025 |
| 684 | Westfield Energy Corp. | | Oil & Gas Operator | Mar 1991 |
| 685 | Westgate Oil Com | | Oil Operator | Mar 1993 |
| 686 | Westgate Oil Company, Inc. | Eureka, KS 67045 | Oil Operator | Aug 2025 |
| 687 | Westgate Petroleum, Inc. | Fritch, TX 79036 | Oil & Gas Operator | Nov 2001 |
| 688 | Westhall Associates, Inc. | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Aug 1997 |
| 689 | Westico Energy Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2004 |
| 690 | Westinghouse Elec Co LLC | Monroeville, PA 15146-2808 | Gas Operator | Dec 2024 |
| 691 | Westlake Energy Consultants Corp | Thousand Oaks, CA 91362 | Oil & Gas Operator | Aug 2003 |
| 692 | Westlake Energy Consultants, Inc. | Westlake VIllage, CA 91362 | Gas Operator | Dec 2019 |
| 693 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 694 | Westlands Resources Corporation | Monrovia, CA 91016 | Oil & Gas Operator | Oct 2025 |
| 695 | Westmore Drillin | | Oil & Gas Operator | Oct 1995 |
| 696 | Westmore Drilling Company, Inc. | Lawrence, KS 66047 | Oil & Gas Operator | Dec 2019 |
| 697 | Westmoreland Gas, LLC | | Oil & Gas Operator | Dec 2021 |
| 698 | Westneft LLC | Brooklyn, NY 11204 | Oil Operator | Oct 2025 |
| 699 | Westoil LLC | Austin, TX 78747 | Oil & Gas Operator | Oct 2025 |
| 700 | Weston Management & Operations Group | Centreville, MD 21617 | Oil Operator | May 1997 |