| 1001 | Hi-Kat Petroleum Company | Liberal, KS 67905-1261 | Oil & Gas Operator | May 2014 |
| 1002 | Hi-Mi Exploration, LLC | Alvaton, KY 42122 | Oil & Gas Operator | Dec 2022 |
| 1003 | Hi-Pro Production | Gillette, WY 82717 | Gas Operator | Nov 2003 |
| 1004 | Hiawatha Exploration Company | Oklahoma City, OK 73116-7326 | Oil & Gas Operator | Mar 2009 |
| 1005 | Hibbard Energy, LP | Whitehouse, TX 75791 | Oil & Gas Operator | Feb 2026 |
| 1006 | Hibbard-Frost-Smith | | Oil & Gas Operator | Apr 1990 |
| 1007 | Hibbert R E Estate Of | Houston, TX 77002-3211 | Oil & Gas Operator | Apr 2015 |
| 1008 | Hibernia Resources III, LLC | Houston, TX 77056 | Oil & Gas Operator | Nov 2023 |
| 1009 | Hibernia Resources IV, LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2026 |
| 1010 | Hibernia Resources, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2014 |
| 1011 | Hibernian Compan | | Oil & Gas Operator | Feb 1991 |
| 1012 | Hickey, Jeff | Whitesville, KY 42378 | Oil Operator | Dec 2023 |
| 1013 | Hickey, Kevin F. & Mary | Akron, NY 14001 | Gas Operator | Dec 2024 |
| 1014 | Hickman & Ickert | Olney, TX 76374 | Oil & Gas Operator | Feb 2002 |
| 1015 | Hickman Richard W | Columbus, OH 43220 | Oil & Gas Operator | Dec 1989 |
| 1016 | Hickman, Chad | Burkesville, KY 42717 | Oil Operator | Dec 2023 |
| 1017 | Hickman, Johnny | | Oil & Gas Operator | Oct 2011 |
| 1018 | Hickman-Jordan-Halligan Ranches | Blackwell, TX 79506 | Oil & Gas Operator | Feb 1998 |
| 1019 | Hickory Petroleum Inc. | Abilene, TX 79604 | Oil & Gas Operator | Jun 2013 |
| 1020 | Hickory-National Co. | | Oil Operator | Dec 1986 |
| 1021 | Hickox Oil Texas Company, Inc. | Mobile, AL 36689 | Oil & Gas Operator | Feb 1996 |
| 1022 | Hickox, I. N. | | Oil Operator | Nov 1967 |
| 1023 | Hicks Exploration, LLC | Dover, OK 73734 | Gas Operator | Dec 2024 |
| 1024 | Hicks Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2012 |
| 1025 | Hicks Production Co. | | Oil & Gas Operator | Apr 1991 |
| 1026 | Hicks, Robert F. | San Angelo, TX 76904 | Oil & Gas Operator | Mar 1994 |
| 1027 | Hicon Gas Producers, Inc. | New York, NY 10110 | Oil & Gas Operator | Oct 1999 |
| 1028 | Hidalgo Oil & Exploration Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Feb 2026 |
| 1029 | Hiebert & Wedel | | Oil & Gas Operator | May 1995 |
| 1030 | Hiebert, D. O. Lewis | McPherson, KS 67460 | Oil Operator | Feb 1999 |
| 1031 | Higginbotham, O. V. | Cedar Park, TX 78613 | Oil & Gas Operator | Jul 1996 |
| 1032 | Higginbottom Engineering, Inc. | Liberal, KS 67905 | Oil & Gas Operator | Sep 2025 |
| 1033 | Higgins Oil & Ga | | Oil Operator | Apr 1992 |
| 1034 | High Bluff Operating, LLC | Littleton, CO 80161 | Oil & Gas Operator | May 2018 |
| 1035 | High Chapparal Oil Company | Plntersville, TX 77363 | Oil & Gas Operator | Aug 2003 |
| 1036 | High Desert Resources, L.L.C. | Midland, TX 79704 | Oil Operator | Feb 2026 |
| 1037 | High Energy | Cushing, OK 74023 | Oil & Gas Operator | Nov 2025 |
| 1038 | High Island Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 1039 | High Island Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2017 |
| 1040 | High McDonald Operating Co | Norman, OK 73072-7607 | Oil Operator | Oct 2025 |
| 1041 | High Mountain Oil & Gas | Hobbs, NM 88240 | Oil & Gas Operator | Jan 2019 |
| 1042 | High Mountain Oil & Gas, LLC | Hobbs, NM 88240 | Oil & Gas Operator | Feb 2026 |
| 1043 | High Noon Resources, LLC | Allen, TX 75013 | Oil & Gas Operator | Feb 2026 |
| 1044 | High Plains Energy LLC | | Oil & Gas Operator | May 2017 |
| 1045 | High Plains Gas LLC | Gillette, WY 82717 | Gas Operator | Aug 2014 |
| 1046 | High Plains Gas Systems, Inc. | Houston, TX 77019 | Oil & Gas Operator | Feb 2026 |
| 1047 | High Plains Oil | | Oil Operator | Jun 1989 |
| 1048 | High Plains Operating Co | | Oil & Gas Operator | Nov 1993 |
| 1049 | High Plains Operating, LLC | | Oil Operator | Dec 2025 |
| 1050 | High Plains Petroleum Corp | Boulder, CO 80305 | Oil & Gas Operator | Jan 2021 |
| 1051 | High Plains Production, LLC | Murray, KY 42071 | Oil & Gas Operator | Dec 2024 |
| 1052 | High Point Produ | | Gas Operator | May 1996 |
| 1053 | High River Res Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 1054 | High River Resources Operating, LLC | Farmington, NM 87401 | Oil & Gas Operator | Nov 2025 |
| 1055 | High Sierra Operating, LTD. | Canyon Lake, TX 78133 | Oil & Gas Operator | Mar 2008 |
| 1056 | High Sierra Water Services Mid Continent LLC | Denver, CO 80209 | Oil Operator | Feb 2010 |
| 1057 | High Sky Oil & Gas | Midland, TX 79705 | Oil & Gas Operator | Jun 2008 |
| 1058 | High Sky Partners LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2015 |
| 1059 | High Splint Gas & Oil, Inc | Greenville, KY 42345 | Oil Operator | Dec 2023 |
| 1060 | High Summit Oil & Gas Inc | | Oil & Gas Operator | Sep 1987 |
| 1061 | High-Hope Oil And Gas, Inc | | Oil & Gas Operator | Mar 2017 |
| 1062 | High-Line Production Services LLC | | Oil & Gas Operator | Sep 2025 |
| 1063 | Higher Standard Oil Company,Inc. | Frisco, TX 75034 | Oil Operator | Feb 2026 |
| 1064 | Highfill Bob W | Claremore, OK 74018-2595 | Oil Operator | Jun 2005 |
| 1065 | Highground, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Feb 2026 |
| 1066 | Highhouse James R | Warren, PA 16365-7550 | Oil & Gas Operator | Dec 2008 |
| 1067 | Highland Exploration | | Oil Operator | Sep 1979 |
| 1068 | Highland Minerals Inc | Tulsa, OK 74145-7627 | Oil & Gas Operator | Apr 2015 |
| 1069 | Highland Oil & Gas Co | Mason, OH 45040 | Oil Operator | Dec 2022 |
| 1070 | Highland Oil & Gas LLC | Houston, TX 77079-7220 | Oil & Gas Operator | Feb 2015 |
| 1071 | Highland Oil Co. | | Oil Operator | Mar 1953 |
| 1072 | Highland Production Company | Midland, TX 79701 | Oil & Gas Operator | Mar 1996 |
| 1073 | Highland Resources, Inc. | | Oil & Gas Operator | Dec 2004 |
| 1074 | Highlander Oil & Gas Assets LLC | | Gas Operator | Jan 2025 |
| 1075 | Highlands Operating Co., Inc. | | Oil & Gas Operator | May 1990 |
| 1076 | Highline Exploration, Inc. | Tuscaloosa, AL 35402 | Gas Operator | Nov 2020 |
| 1077 | Highman Oil & Gas LLC | Woodsfield, OH 43793 | Oil & Gas Operator | Dec 2024 |
| 1078 | Highmark Energy Operating LLC | Dallas, TX 75222 | Oil & Gas Operator | Feb 2026 |
| 1079 | Highmount Black Warrior Basin, LLC | | Gas Operator | Jul 2010 |
| 1080 | Highmount Expl & Prod Texas LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2014 |
| 1081 | Highmount Midwest Energy LLC | | Oil & Gas Operator | Sep 2011 |
| 1082 | Highmount Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2014 |
| 1083 | Highpeak Energy Holdings, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 1084 | Highpoint Energy LLC | | Oil & Gas Operator | Nov 2022 |
| 1085 | Highpointe Oil & Gas LLC | Indiana, PA 15701-8944 | Gas Operator | Dec 2025 |
| 1086 | Hight Exploration Co | Lamont, OK 74643 | Oil & Gas Operator | Jan 1999 |
| 1087 | Hightower Energy LLC | Cushing, OK 74023-6370 | Oil & Gas Operator | Dec 2025 |
| 1088 | Hightower Exploration | Kilgore, TX 75662 | Oil & Gas Operator | Feb 2026 |
| 1089 | Hightower Oil & Gas | Cairo, IL 62914-0401 | Oil Operator | Nov 2014 |
| 1090 | Highway 15 SWD LLC | Shattuck, OK 73858 | Oil Operator | Oct 2021 |
| 1091 | Highway 60 SWD LLC | Shattuck, OK 73858-0848 | Oil Operator | Jul 2019 |
| 1092 | Hikcott Oil | Wilson, OK 73463-6537 | Oil Operator | Jan 2014 |
| 1093 | Hiko Bell Mining & Oil Co | Vernal, UT 84078 | Oil & Gas Operator | Oct 2003 |
| 1094 | Hilbers Oil & Gas | Archer City, TX 76351 | Oil & Gas Operator | Oct 2002 |
| 1095 | Hilburn Ind., Inc. | | Oil Operator | Jan 1978 |
| 1096 | Hilcorp Alaska, LLC | | Oil & Gas Operator | Jan 2026 |
| 1097 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Feb 2026 |
| 1098 | Hilcorp North Slope, LLC | | Oil & Gas Operator | Dec 2025 |
| 1099 | Hilden Oil Co Inc | | Oil & Gas Operator | Oct 2024 |
| 1100 | Hildreth, Roy G & Son Inc | Spencer, WV 25276 | Oil & Gas Operator | Dec 2021 |