| 801 | Altex Energy Corporation | Oklahoma City, OK 73142-1920 | Oil & Gas Operator | Mar 2015 |
| 802 | Altex Inc | Corning, OH 43730 | Oil & Gas Operator | Dec 1985 |
| 803 | Altex Oil Company | Breckenridge, CO 80424 | Oil & Gas Operator | Dec 2005 |
| 804 | Altex Oil Corp | Breckenridge, CO 80424-1057 | Oil & Gas Operator | Dec 1999 |
| 805 | Altex Resources, Inc. | Carney, OK 74832 | Oil & Gas Operator | Mar 2015 |
| 806 | Altex Resources, Inc. (A Texas Corp.) | FT. Worth, TX 76107 | Oil Operator | Apr 1997 |
| 807 | Altheirs Oil, Inc. | Corning, OH 43730 | Oil & Gas Operator | Dec 2024 |
| 808 | Altier Brothers Inc | Corning, OH 43730 | Oil & Gas Operator | Dec 2024 |
| 809 | Altier Petroleum Inc | Corning, OH 43730 | Oil & Gas Operator | Dec 2024 |
| 810 | Altman Energy, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Dec 2025 |
| 811 | Alto Minerals, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2019 |
| 812 | Alton Oil LLC | Winfield, KS 67156 | Oil & Gas Operator | Jun 2025 |
| 813 | Altos Petroleum Serv Inc | Bristolville, OH 44402 | Oil & Gas Operator | Dec 1992 |
| 814 | Altura Energy LTD. | Houston, TX 77210 | Oil & Gas Operator | Apr 2000 |
| 815 | Alturas Energy, LLC | Sidney, MT 59270 | Oil Operator | Mar 2022 |
| 816 | Altus Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Jul 1984 |
| 817 | Alumni Oil LLC | Plano, TX 75024 | Oil Operator | Dec 2025 |
| 818 | Alumni Petroleum And Resource Management Corp | | Oil & Gas Operator | Mar 1988 |
| 819 | Alva J. Dixon | | Oil & Gas Operator | Aug 1991 |
| 820 | Alvarado 2014 LLC | Houston, TX 77027 | Oil & Gas Operator | Dec 2025 |
| 821 | Alvey Partners | Slaton, TX 79364 | Gas Operator | Dec 2025 |
| 822 | Alvin & Roger Wilson | | Oil Operator | Dec 2007 |
| 823 | Alvin Wilson, Et Al | | Oil Operator | May 1991 |
| 824 | Alyaha Energy, LLC | Dumas, TX 79029 | Oil & Gas Operator | Dec 2025 |
| 825 | Alyana Energy Corporation | Houston, TX 77227 | Oil & Gas Operator | Apr 1995 |
| 826 | Alyndson Oil & Gas Inc. | Alice, TX 78333 | Oil & Gas Operator | Jun 2000 |
| 827 | Am Oil Company | Cyril, OK 73029 | Oil & Gas Operator | Sep 2025 |
| 828 | Am-Tek Oil Inc | Spokane, WA 99201 | Oil & Gas Operator | Dec 2023 |
| 829 | Am-West Petroleum Inc | Upton, WY 82730 | Oil & Gas Operator | Sep 2015 |
| 830 | Amac Energy, L.L.C. | The Woodlands, TX 77381 | Oil & Gas Operator | Dec 2025 |
| 831 | Amac Inc | Newark, OH 43055 | Oil & Gas Operator | Dec 1989 |
| 832 | Amalgamated Bonanza Petr. LTD. | | Oil & Gas Operator | Apr 1980 |
| 833 | Amalgamated Sludge NM, LLC | Dallas, TX 75208 | Gas Operator | Sep 2025 |
| 834 | Amarex Inc | | Oil & Gas Operator | Dec 1996 |
| 835 | Amarex Incorpora | | Oil Operator | Feb 1985 |
| 836 | Amarillo Exploration, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Dec 2025 |
| 837 | Amarillo Natural Gas, Inc. | Amarillo, TX 79119 | Gas Operator | Jul 1996 |
| 838 | Amarillo Oil Company | | Oil & Gas Operator | Aug 1980 |
| 839 | Amaroq Resources, LLC | | Gas Operator | Oct 2025 |
| 840 | Amata Oils Inc | | Oil Operator | Dec 2015 |
| 841 | Amax Oil & Gas Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Nov 2014 |
| 842 | Amax Petroleum C | | Oil & Gas Operator | Aug 1986 |
| 843 | Amax Petroleum Corporation | Houston, TX 77042 | Oil & Gas Operator | Dec 2012 |
| 844 | Amax Petroluem Corp. | | Oil & Gas Operator | Nov 1983 |
| 845 | Amazon Exploration LLC | | Oil Operator | Apr 2016 |
| 846 | Amazon Royalties, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | Dec 2025 |
| 847 | Ambassador Oil Company, LLC | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 848 | Ambassador Petroleum, Inc. | Katy, TX 77494 | Oil & Gas Operator | Dec 2025 |
| 849 | Amber Oil Compan | | Oil Operator | Aug 1995 |
| 850 | Amberex Corporation | Denver, CO 80237 | Oil & Gas Operator | Sep 1984 |
| 851 | Amble Petroleum Co., Inc. | Tuscola, TX 79562 | Oil Operator | Sep 2025 |
| 852 | Ambra Oil & Gas Company | Rangely, CO 81648 | Oil & Gas Operator | Jul 2006 |
| 853 | Ambrit Energy Corp. | Garland, TX 75044 | Oil & Gas Operator | Jun 2003 |
| 854 | Ambrotra Energy LLC | Medicine Lodge, KS 67104 | Oil Operator | May 2025 |
| 855 | Amcole Energy Corporation | Dallas, TX 75231 | Oil & Gas Operator | Aug 2000 |
| 856 | Amcon Resources | Oklahoma City, OK 73102 | Gas Operator | Jul 2000 |
| 857 | Amcon Resources, Inc. | Oklahoma City, OK 73101 | Gas Operator | Jun 2016 |
| 858 | Amedan Resources, Inc. | Chickasha, OK 73023 | Oil & Gas Operator | Mar 2008 |
| 859 | Amelia Exploration LLC | Marble Falls, TX 78654 | Oil Operator | Dec 2025 |
| 860 | Amen Oil LLC | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 861 | Amend Energy Company | Houston, TX 77227 | Oil & Gas Operator | Apr 2002 |
| 862 | Amer Energy Develop Inc | Columbus, OH 43220 | Oil & Gas Operator | Dec 1989 |
| 863 | Amer Exploration Co | Plymouth Meeting, PA 19462-1640 | Oil & Gas Operator | Dec 2008 |
| 864 | Amer Natural Resources LLC | Rural Valley, PA 16249-0306 | Oil & Gas Operator | Dec 2018 |
| 865 | Amer Oil & Gas LLC | MT Morris, PA 15349 | Oil & Gas Operator | Sep 2025 |
| 866 | Amer-Tex Energy Inc | Oklahoma City, OK 73116-9037 | Oil & Gas Operator | Feb 2012 |
| 867 | Amer. Intl. Petroleum Corp. | | Oil & Gas Operator | Dec 1990 |
| 868 | Amerac Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jun 2013 |
| 869 | Amerada Hess Corp-Placid | | Gas Operator | Sep 1990 |
| 870 | Amerada Hess Corp. Unit Operator | | Oil & Gas Operator | Dec 1986 |
| 871 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 872 | Amerada Hess-Ethyl Corporation | | Oil & Gas Operator | Sep 1990 |
| 873 | Ameredev New Mexico, LLC | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 874 | Ameredev Operating, LLC | Austin, TX 78746 | Oil & Gas Operator | Dec 2025 |
| 875 | Amerex Corporation | Edmond, OK 73013-1044 | Oil & Gas Operator | Apr 2020 |
| 876 | American B. C. Resources | | Oil & Gas Operator | Oct 1985 |
| 877 | American Barter Petroleum Inc. | | Oil & Gas Operator | Jun 1993 |
| 878 | American Capital Corporation | San Marcos, CA 92069 | Oil & Gas Operator | Sep 2014 |
| 879 | American Cascade Energy, Inc. | Barker, TX 77413 | Oil & Gas Operator | Dec 2025 |
| 880 | American Casing Crews, Inc. | | Oil Operator | Dec 1979 |
| 881 | American Coastal Energy, Inc. | Houston, TX 77225 | Oil & Gas Operator | May 2008 |
| 882 | American Cometra, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2008 |
| 883 | American Delta Corporation | Portland, TX 78374 | Oil & Gas Operator | Jun 2013 |
| 884 | American Domestic MGMT Inc | Tulsa, OK 74155 | Oil & Gas Operator | Apr 2015 |
| 885 | American Eagle Energy Corporation | | Oil & Gas Operator | Oct 2015 |
| 886 | American Eagle Oil | Casper, WY 82605 | Oil & Gas Operator | Dec 2012 |
| 887 | American Eagle Operating LLC | Gainesville, TX 76240 | Oil Operator | Dec 2025 |
| 888 | American Eagle Operating, Inc. | Spring, TX 77386 | Oil Operator | Aug 2010 |
| 889 | American Eagle Resources, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2025 |
| 890 | American Energie | | Oil & Gas Operator | May 1995 |
| 891 | American Energies Pipeline, LLC | Dallas, TX 75207 | Oil & Gas Operator | Jan 2015 |
| 892 | American Energy | Abilene, TX 79604 | Oil & Gas Operator | Jul 2004 |
| 893 | American Energy Associates Inc | Cortland, OH 44410 | Oil & Gas Operator | Dec 2024 |
| 894 | American Energy Corporation | Bealsville, OH 43716 | Oil & Gas Operator | Dec 2019 |
| 895 | American Energy Holdings, LLC | Jane Lew, WV 26378 | Oil & Gas Operator | Dec 2021 |
| 896 | American Energy LLC | Lake Zurich, IL 60047-0129 | Oil & Gas Operator | Nov 2014 |
| 897 | American Energy Op. Corp.,The | Houston, TX 77099 | Oil & Gas Operator | Dec 2025 |
| 898 | American Energy Operations Inc | Houston, TX 77002 | Oil & Gas Operator | Nov 1992 |
| 899 | American Energy Partners Inc | Boerne, TX 78006 | Oil & Gas Operator | Dec 2011 |
| 900 | American Energy Recovery Inc | Oklahoma City, OK 73123-0549 | Oil & Gas Operator | Aug 2017 |