| 901 | Herschap Bros. | Bruni, TX 78344 | Oil & Gas Operator | Jun 2025 |
| 902 | Hershey Oil | Pasadena, CA 91103 | Oil & Gas Operator | Dec 1988 |
| 903 | Hershey Oil Corporation | Seminole, TX 79360 | Oil & Gas Operator | Jul 1992 |
| 904 | Hertel Oil Company | | Oil Operator | Nov 2018 |
| 905 | Hertel Oil Company LLC | Hays, KS 67601 | Oil Operator | Feb 2025 |
| 906 | Herv Oil, LLC | Oklahoma City, OK 73116 | Oil Operator | Mar 2025 |
| 907 | Herzfeld Fabricators Inc | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2017 |
| 908 | Hesperus Energy II LLC | | Oil Operator | Feb 2025 |
| 909 | Hess Bakken Investments II, LLC | | Oil & Gas Operator | Apr 2025 |
| 910 | Hess Bros. DRLG. Co. | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2008 |
| 911 | Hess Co2 Resources LLC | Seminole, TX 79360 | Gas Operator | Aug 2017 |
| 912 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 913 | Hess Corporation, A De Corp. | | Oil & Gas Operator | Oct 2006 |
| 914 | Hess Ohio Developments LLC | Houston, TX 77010 | Oil & Gas Operator | Sep 2018 |
| 915 | Hess Ohio Resources LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2014 |
| 916 | Hess Oil Company | McPherson, KS 67460 | Oil & Gas Operator | Feb 2025 |
| 917 | Hess Production | Quitaque, TX 79255 | Oil & Gas Operator | Jun 2025 |
| 918 | Hess Seminole Assets LLC | Seminole, TX 79360 | Oil & Gas Operator | Aug 2017 |
| 919 | Hess, Jay E. | Andover, NY 14806 | Oil & Gas Operator | Dec 2023 |
| 920 | Hess, Jerry Operating Co. | Muenster, TX 76252 | Oil & Gas Operator | Jun 2025 |
| 921 | Hesse Petroleum Co.,L.L.C. | Wichita, KS 67208 | Oil & Gas Operator | Feb 2025 |
| 922 | Hessert Edward C | | Oil & Gas Operator | Sep 1993 |
| 923 | Hessert Loc Inc | Carl Junction, MO 64834 | Oil Operator | Dec 2009 |
| 924 | Hester Jr J C | Lawton, OK 73502-1887 | Oil & Gas Operator | Oct 1997 |
| 925 | Hester, Harold & Betty | Bowling Green, KY 42101 | Oil Operator | Dec 2023 |
| 926 | Heston Oil Company | Tulsa, OK 74108 | Oil & Gas Operator | Mar 2005 |
| 927 | Hett Oil & Gas, LLC | Lincolnville, KS 66858 | Oil & Gas Operator | Feb 2025 |
| 928 | Heuston Oil LLC | Bartlesville, OK 74006 | Oil & Gas Operator | Apr 2020 |
| 929 | Hewitt Energy Group, Inc. | Salt Lake City, UT 84111 | Oil & Gas Operator | Apr 2015 |
| 930 | Hewitt Oil, LLC | Bolivar, NY 14715 | Oil & Gas Operator | Dec 2023 |
| 931 | Hewitt, Alan P. | Midland, TX 79702 | Oil & Gas Operator | Aug 1997 |
| 932 | Hewitt, Douglas R | | Oil Operator | Jul 2024 |
| 933 | Hewitt, Robert J. | Victoria, TX 77901 | Oil & Gas Operator | Jun 2004 |
| 934 | Hexadyne Energy Corp. | | Oil & Gas Operator | Dec 2013 |
| 935 | Hexagon Oil And Gas Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Jun 2025 |
| 936 | Hexp Operating, LLC | Midland, TX 79705 | Oil & Gas Operator | Jun 2025 |
| 937 | Heydrick Petroleum Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2025 |
| 938 | Hez Petroleum Company | Graham, TX 76450 | Oil & Gas Operator | Jun 2025 |
| 939 | HG Energy II Appalachia, LLC | | Oil & Gas Operator | Mar 2022 |
| 940 | HG Energy LLC | Parkersburg, WV 26101 | Oil & Gas Operator | Dec 2021 |
| 941 | HG Oil Holdings, LLC | Hoisington, KS 67544 | Oil & Gas Operator | Feb 2025 |
| 942 | HG Operating LLC | Plano, TX 75026 | Oil & Gas Operator | Jun 2025 |
| 943 | HGB Oil Company | Denver, CO 80224 | Oil Operator | Mar 2006 |
| 944 | HGH Energy, Inc. | | Oil & Gas Operator | Jun 2001 |
| 945 | Hgi Corporation | Nada, TX 77460 | Oil & Gas Operator | Apr 2016 |
| 946 | HGN Operating Co. | Abilene, TX 79604 | Oil & Gas Operator | Jul 2014 |
| 947 | HGN Operating I, LLC | Abilene, TX 79604 | Oil & Gas Operator | Jun 2025 |
| 948 | HH&F Partners | Katy, TX 77450 | Oil & Gas Operator | Sep 2019 |
| 949 | HHH & G Oil Co | Owasso, OK 74055 | Oil Operator | Jun 2020 |
| 950 | HHL Development Inc | Garber, OK 73738 | Oil & Gas Operator | Jan 2025 |
| 951 | Hi - Mountain Energy Corporation | Odessa, TX 79762 | Oil & Gas Operator | Jun 2025 |
| 952 | Hi Plains Hydrocarbons, Inc. | Sunray, TX 79086 | Oil & Gas Operator | Oct 2002 |
| 953 | Hi Snyder/Snyder Oil & Gas Inc | Dover, OH 44622 | Oil & Gas Operator | Dec 2019 |
| 954 | Hi-Kat Petroleum | | Oil Operator | Mar 1990 |
| 955 | Hi-Kat Petroleum Company | Liberal, KS 67905-1261 | Oil & Gas Operator | May 2014 |
| 956 | Hi-Mi Exploration, LLC | Alvaton, KY 42122 | Oil & Gas Operator | Dec 2022 |
| 957 | Hi-Pro Production | Gillette, WY 82717 | Gas Operator | Nov 2003 |
| 958 | Hiawatha Exploration Company | Oklahoma City, OK 73116-7326 | Oil & Gas Operator | Mar 2009 |
| 959 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Jun 2025 |
| 960 | Hibbard-Frost-Smith | | Oil & Gas Operator | Apr 1990 |
| 961 | Hibbert R E Estate Of | Houston, TX 77002-3211 | Oil & Gas Operator | Apr 2015 |
| 962 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 963 | Hibernia Resources IV, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2025 |
| 964 | Hibernia Resources, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2014 |
| 965 | Hibernian Compan | | Oil & Gas Operator | Feb 1991 |
| 966 | Hickey, Jeff | Whitesville, KY 42378 | Oil Operator | Dec 2023 |
| 967 | Hickey, Kevin F. & Mary | Akron, NY 14001 | Gas Operator | Dec 2023 |
| 968 | Hickman & Ickert | Olney, TX 76374 | Oil & Gas Operator | Feb 2002 |
| 969 | Hickman, Chad | Burkesville, KY 42717 | Oil Operator | Dec 2023 |
| 970 | Hickman, Johnny | | Oil & Gas Operator | Oct 2011 |
| 971 | Hickman-Jordan-Halligan Ranches | Blackwell, TX 79506 | Oil & Gas Operator | Feb 1998 |
| 972 | Hickory Petroleum Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2013 |
| 973 | Hickory-National Co. | | Oil Operator | Dec 1986 |
| 974 | Hickox Oil Texas Company, Inc. | Mobile, AL 36689 | Oil & Gas Operator | Feb 1996 |
| 975 | Hickox, I. N. | | Oil Operator | Nov 1967 |
| 976 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Feb 2025 |
| 977 | Hicks Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2012 |
| 978 | Hicks Production Co. | | Oil & Gas Operator | Apr 1991 |
| 979 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 980 | Hidalgo Oil & Exploration Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Jun 2025 |
| 981 | Hiebert & Wedel | | Oil & Gas Operator | May 1995 |
| 982 | Hiebert, D. O. Lewis | McPherson, KS 67460 | Oil Operator | Feb 1999 |
| 983 | Higginbotham, O. V. | Cedar Park, TX 78613 | Oil & Gas Operator | Jul 1996 |
| 984 | Higginbottom Engineering, Inc. | Liberal, KS 67905 | Oil & Gas Operator | Feb 2025 |
| 985 | Higgins Oil & Ga | | Oil Operator | Apr 1992 |
| 986 | High Bluff Operating, LLC | Littleton, CO 80161 | Oil & Gas Operator | May 2018 |
| 987 | High Chapparal Oil Company | Plntersville, TX 77363 | Oil & Gas Operator | Aug 2003 |
| 988 | High Desert Resources, L.L.C. | Midland, TX 79704 | Oil Operator | Jun 2025 |
| 989 | High Energy | Cushing, OK 74023 | Oil & Gas Operator | Feb 2025 |
| 990 | High Island Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2025 |
| 991 | High Island Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2017 |
| 992 | High McDonald Operating Co | Norman, OK 73072-7607 | Oil Operator | Dec 2024 |
| 993 | High Mountain Oil & Gas | Hobbs, NM 88240 | Oil & Gas Operator | Jan 2019 |
| 994 | High Mountain Oil & Gas, LLC | Hobbs, NM 88240 | Oil & Gas Operator | Jun 2025 |
| 995 | High Noon Resources, LLC | Allen, TX 75013 | Oil & Gas Operator | Jun 2025 |
| 996 | High Plains Energy LLC | | Oil & Gas Operator | May 2017 |
| 997 | High Plains Gas LLC | Gillette, WY 82717 | Gas Operator | Aug 2014 |
| 998 | High Plains Gas Systems, Inc. | Houston, TX 77019 | Oil & Gas Operator | Jun 2025 |
| 999 | High Plains Oil | | Oil Operator | Jun 1989 |
| 1000 | High Plains Operating Co | | Oil & Gas Operator | Nov 1993 |