| 901 | Heston Oil Company | Tulsa, OK 74108 | Oil & Gas Operator | Mar 2005 |
| 902 | Hett Oil & Gas, LLC | Lincolnville, KS 66858 | Oil & Gas Operator | Feb 2026 |
| 903 | Heuston Oil LLC | Bartlesville, OK 74006 | Oil & Gas Operator | Apr 2020 |
| 904 | Hewitt Energy Group Inc | Salt Lake City, UT 84111 | Oil & Gas Operator | Apr 2015 |
| 905 | Hewitt Oil, LLC | Bolivar, NY 14715 | Oil & Gas Operator | Dec 2024 |
| 906 | Hewitt, Alan P. | Midland, TX 79702 | Oil & Gas Operator | Aug 1997 |
| 907 | Hewitt, Douglas R | | Oil Operator | Nov 2025 |
| 908 | Hewitt, Robert J. | Victoria, TX 77901 | Oil & Gas Operator | Jun 2004 |
| 909 | Hexadyne Energy Corp. | | Oil & Gas Operator | Dec 2013 |
| 910 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Jun 2026 |
| 911 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 912 | Heydrick Petroleum Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 913 | Hez Petroleum Company | Graham, TX 76450 | Oil & Gas Operator | Jun 2026 |
| 914 | HG Energy II Appalachia, LLC | | Oil & Gas Operator | Mar 2022 |
| 915 | HG Energy LLC | Parkersburg, WV 26101 | Oil & Gas Operator | Dec 2021 |
| 916 | HG Oil Holdings, LLC | Hoisington, KS 67544 | Oil & Gas Operator | Feb 2026 |
| 917 | HG Operating LLC | Plano, TX 75026 | Oil & Gas Operator | Jun 2026 |
| 918 | HGH Energy, Inc. | | Oil & Gas Operator | Jun 2001 |
| 919 | Hgi Corporation | Nada, TX 77460 | Oil & Gas Operator | Apr 2016 |
| 920 | HGN Operating Company, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 921 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Jun 2026 |
| 922 | HHH & G Oil Co | Owasso, OK 74055 | Oil Operator | Jun 2020 |
| 923 | HHL Development Inc | Garber, OK 73738 | Oil & Gas Operator | Feb 2026 |
| 924 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Jun 2026 |
| 925 | Hi Plains Hydrocarbons, Inc. | Sunray, TX 79086 | Oil & Gas Operator | Oct 2002 |
| 926 | Hi Snyder/Snyder Oil & Gas Inc | Dover, OH 44622 | Oil & Gas Operator | Dec 2019 |
| 927 | Hi-Kat Petroleum | | Oil Operator | Mar 1990 |
| 928 | Hi-Kat Petroleum Company | Liberal, KS 67905-1261 | Oil & Gas Operator | May 2014 |
| 929 | Hi-Mi Exploration, LLC | Alvaton, KY 42122 | Oil & Gas Operator | Dec 2022 |
| 930 | Hi-Pro Production | Gillette, WY 82717 | Gas Operator | Nov 2003 |
| 931 | Hiawatha Exploration Company | Oklahoma City, OK 73116-7326 | Oil & Gas Operator | Mar 2009 |
| 932 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Jun 2026 |
| 933 | Hibbard-Frost-Smith | | Oil & Gas Operator | Apr 1990 |
| 934 | Hibbert R E Estate Of | Houston, TX 77002-3211 | Oil & Gas Operator | Apr 2015 |
| 935 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 936 | Hibernia Resources IV, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2026 |
| 937 | Hibernia Resources, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2014 |
| 938 | Hibernian Compan | | Oil & Gas Operator | Feb 1991 |
| 939 | Hickey, Jeff | Whitesville, KY 42378 | Oil Operator | Dec 2023 |
| 940 | Hickey, Kevin F. & Mary | Akron, NY 14001 | Gas Operator | Dec 2024 |
| 941 | Hickman & Ickert | Olney, TX 76374 | Oil & Gas Operator | Feb 2002 |
| 942 | Hickman, Johnny | | Oil & Gas Operator | Oct 2011 |
| 943 | Hickman-Jordan-Halligan Ranches | Blackwell, TX 79506 | Oil & Gas Operator | Feb 1998 |
| 944 | Hickory Petroleum Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2013 |
| 945 | Hickory-National Co. | | Oil Operator | Dec 1986 |
| 946 | Hickox Oil Texas Company, Inc. | Mobile, AL 36689 | Oil & Gas Operator | Feb 1996 |
| 947 | Hickox, I. N. | | Oil Operator | Nov 1967 |
| 948 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Oct 2024 |
| 949 | Hicks Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2012 |
| 950 | Hicks Production Co. | | Oil & Gas Operator | Apr 1991 |
| 951 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 952 | Hidalgo Oil & Exploration Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Jun 2026 |
| 953 | Hidden Oaks Oil Company, LLC | New Braunfels, TX 78132 | Oil Operator | Jun 2026 |
| 954 | Hiebert & Wedel | | Oil & Gas Operator | May 1995 |
| 955 | Hiebert, D. O. Lewis | McPherson, KS 67460 | Oil Operator | Feb 1999 |
| 956 | Higginbotham, O. V. | Cedar Park, TX 78613 | Oil & Gas Operator | Jul 1996 |
| 957 | Higginbottom Engineering, Inc. | Liberal, KS 67905 | Oil & Gas Operator | Feb 2026 |
| 958 | Higgins Oil & Ga | | Oil Operator | Apr 1992 |
| 959 | High Bluff Operating, LLC | Littleton, CO 80161 | Oil & Gas Operator | May 2018 |
| 960 | High Chapparal Oil Company | Plntersville, TX 77363 | Oil & Gas Operator | Aug 2003 |
| 961 | High Desert Resources, L.L.C. | Midland, TX 79704 | Oil Operator | Jun 2026 |
| 962 | High Energy | Cushing, OK 74023 | Oil & Gas Operator | Feb 2026 |
| 963 | High Island Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 964 | High Island Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2017 |
| 965 | High McDonald Operating Co | Norman, OK 73072-7607 | Oil Operator | Jan 2026 |
| 966 | High Mountain Oil & Gas | Hobbs, NM 88240 | Oil & Gas Operator | Jan 2019 |
| 967 | High Mountain Oil & Gas, LLC | Hobbs, NM 88240 | Oil & Gas Operator | Jun 2026 |
| 968 | High Noon Resources, LLC | Allen, TX 75013 | Oil & Gas Operator | Jun 2026 |
| 969 | High Plains Energy LLC | | Oil & Gas Operator | May 2017 |
| 970 | High Plains Gas LLC | Gillette, WY 82717 | Gas Operator | Aug 2014 |
| 971 | High Plains Gas Systems, Inc. | Houston, TX 77019 | Oil & Gas Operator | Jun 2026 |
| 972 | High Plains Oil | | Oil Operator | Jun 1989 |
| 973 | High Plains Operating Co | | Oil & Gas Operator | Nov 1993 |
| 974 | High Plains Operating, LLC | | Oil Operator | May 2026 |
| 975 | High Plains Petroleum Corp | Boulder, CO 80305 | Oil & Gas Operator | Jan 2021 |
| 976 | High Plains Production, LLC | Murray, KY 42071 | Oil & Gas Operator | Dec 2024 |
| 977 | High River Res Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jun 2026 |
| 978 | High River Resources Operating, LLC | Farmington, NM 87401 | Oil & Gas Operator | Apr 2026 |
| 979 | High Sierra Operating, LTD. | Canyon Lake, TX 78133 | Oil & Gas Operator | Mar 2008 |
| 980 | High Sierra Water Services Mid Continent LLC | Denver, CO 80209 | Oil Operator | Feb 2010 |
| 981 | High Sky Oil & Gas | Midland, TX 79705 | Oil & Gas Operator | Jun 2008 |
| 982 | High Sky Partners LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2015 |
| 983 | High Splint Gas & Oil, Inc | Greenville, KY 42345 | Oil Operator | Dec 2023 |
| 984 | High Summit Oil & Gas Inc | | Oil & Gas Operator | Sep 1987 |
| 985 | High-Hope Oil And Gas, Inc | | Oil & Gas Operator | Mar 2017 |
| 986 | High-Line Production Services LLC | | Oil & Gas Operator | Sep 2025 |
| 987 | Higher Standard Oil Company,Inc. | Frisco, TX 75034 | Oil Operator | Jun 2026 |
| 988 | Highfill Bob W | Claremore, OK 74018-2595 | Oil Operator | Jun 2005 |
| 989 | Highground, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Jun 2026 |
| 990 | Highhouse James R | Warren, PA 16365-7550 | Oil & Gas Operator | Dec 2008 |
| 991 | Highland Exploration | | Oil Operator | Sep 1979 |
| 992 | Highland Minerals Inc | Tulsa, OK 74145-7627 | Oil & Gas Operator | Apr 2015 |
| 993 | Highland Oil & Gas Co | Mason, OH 45040 | Oil Operator | Dec 2022 |
| 994 | Highland Oil & Gas LLC | Houston, TX 77079-7220 | Oil & Gas Operator | Feb 2015 |
| 995 | Highland Oil Co. | | Oil Operator | Mar 1953 |
| 996 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 997 | Highland Resources, Inc. | | Oil & Gas Operator | Dec 2004 |
| 998 | Highlander Oil & Gas Assets LLC | | Gas Operator | Jan 2025 |
| 999 | Highlands Operating Co., Inc. | | Oil & Gas Operator | May 1990 |
| 1000 | Highline Exploration, Inc. | Tuscaloosa, AL 35402 | Gas Operator | Nov 2020 |