| 12201 | Hankey Oil Company | Houston, TX 77027 | Oil & Gas Operator | Feb 2010 |
| 12202 | Hankey Operating, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2016 |
| 12203 | Hanks, Christopher Glenn | Gainesville, TX 76240 | Oil & Gas Operator | Jun 2026 |
| 12204 | Hanley & Bird Inc | Tulsa, OK 74119 | Oil & Gas Operator | Dec 2011 |
| 12205 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 12206 | Hanna M A Co | Cleveland, OH 44114-1824 | Oil & Gas Operator | Dec 1991 |
| 12207 | Hanna Oil And Gas Company | Fort Smith, AR 72901 | Oil & Gas Operator | Mar 2026 |
| 12208 | Hannathon Petroleum II, LLC | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 12209 | Hannathon Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 12210 | Hannis Operating, LLC | Olney, TX 76374 | Oil & Gas Operator | Mar 2026 |
| 12211 | Hannold, Allan & Yolanda | Bloomfield, NY 14469 | Gas Operator | Dec 2024 |
| 12212 | Hanoco Inc | Tulsa, OK 74135 | Oil & Gas Operator | Mar 2026 |
| 12213 | Hanover Management Company | | Oil Operator | Aug 1979 |
| 12214 | Hanover Operating Company | Tulsa, OK 74101 | Oil & Gas Operator | Dec 1998 |
| 12215 | Hanselman, Michael D. | Jamestown, NY 14701 | Gas Operator | Dec 2024 |
| 12216 | Hansen Dane G TR | | Oil Operator | Feb 1995 |
| 12217 | Hansen Noel | Avant, OK 74001 | Oil Operator | Aug 2013 |
| 12218 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 12219 | Hansen, Dane G. - Trust | Logan, KS 67646 | Oil Operator | Oct 2013 |
| 12220 | Hanshu Production Company | Darrouzett, TX 79024 | Oil & Gas Operator | Apr 2017 |
| 12221 | Hanshu Production Company, LLC | Nashville, TN 37215 | Gas Operator | Jun 2026 |
| 12222 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 12223 | Hanson Energy | Glencoe, NM 88324 | Oil & Gas Operator | Jul 2008 |
| 12224 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 12225 | Hanson Natural Resources Co. | | Oil & Gas Operator | Nov 1991 |
| 12226 | Hanson Operating Company Inc | Roswell, NM 88202 | Oil & Gas Operator | Mar 2026 |
| 12227 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 12228 | Hanvey Production Co., Inc. | Roanoke, TX 76262 | Oil & Gas Operator | Nov 2012 |
| 12229 | Hanvey, Don H. Oil Interests Inc | Cisco, TX 76437 | Oil & Gas Operator | Jun 2026 |
| 12230 | Happy Hill Operating LLC | Guthrie, OK 73044-7361 | Oil & Gas Operator | Oct 2017 |
| 12231 | Har Ken Oil Company | | Oil & Gas Operator | Dec 2021 |
| 12232 | Har-Ken Agent Ok, LTD | Owensboro, KY 42302 | Oil & Gas Operator | Dec 2023 |
| 12233 | Har-Ken Agent, Ok | Owensboro, KY 42302 | Oil Operator | Jan 2026 |
| 12234 | Harbacek Florence | Holyrood, KS 67450 | Oil Operator | Aug 2002 |
| 12235 | Harbert Energy Corp | Irving, TX 75015-2510 | Oil & Gas Operator | Feb 1993 |
| 12236 | Harbert Energy Corp/Gulf Coast | | Oil & Gas Operator | Dec 1991 |
| 12237 | Harbor Operating, LLC | | Oil & Gas Operator | Dec 1999 |
| 12238 | Harbor Petroleum, LLC | Granbury, TX 76049 | Oil & Gas Operator | Jun 2026 |
| 12239 | Harbor Resources LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jun 2026 |
| 12240 | Harburg* Rudolph W | | Oil & Gas Operator | Nov 2022 |
| 12241 | Harco Land, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Aug 1996 |
| 12242 | Harcon Energy, LLC | Le Roy, KS 66857 | Oil Operator | Dec 2009 |
| 12243 | Harcor Energy Inc. | | Gas Operator | Dec 1999 |
| 12244 | Harcor Exploration Inc. | | Oil Operator | Aug 1989 |
| 12245 | Hard Rock DRLG Co | Falls Of Rough, KY 40119 | Oil Operator | Dec 2023 |
| 12246 | Hard Rock Exploration, Inc. | | Oil & Gas Operator | Dec 2008 |
| 12247 | Hard Rock Operating LLC | | Oil & Gas Operator | May 2022 |
| 12248 | Hardco Inc | Cleveland, OH 44115 | Oil & Gas Operator | Dec 1992 |
| 12249 | Hardee Oil Co. | | Oil Operator | Dec 1994 |
| 12250 | Hardee Petroleum Co., A General PTSHP. | | Oil & Gas Operator | Dec 2013 |
| 12251 | Harden Operating Company Inc | Tulsa, OK 74106-2722 | Oil & Gas Operator | Sep 2006 |
| 12252 | Hardesty Production | Gambier, OH 43022 | Oil & Gas Operator | Dec 2025 |
| 12253 | Hardey Co., The | Shreveport, LA 71107 | Oil & Gas Operator | Jun 2026 |
| 12254 | Hardey Production Company | | Oil Operator | Dec 1998 |
| 12255 | Hardin Energy Co., Inc. | Bigfoot, TX 78005 | Oil Operator | Jun 2026 |
| 12256 | Hardin Hanley E | Zanesville, OH 43701 | Oil & Gas Operator | Dec 1995 |
| 12257 | Hardin Oil Co. | | Oil Operator | Dec 2019 |
| 12258 | Hardin Productions | Okemah, OK 74859 | Oil & Gas Operator | Dec 2006 |
| 12259 | Hardin, W.V. Estate | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2002 |
| 12260 | Harding & Shelton Inc | Oklahoma City, OK 73104-2410 | Oil & Gas Operator | Mar 2026 |
| 12261 | Harding And Shelton Exploration LLC | Oklahoma City, OK 73101-1557 | Oil & Gas Operator | Mar 2026 |
| 12262 | Harding Company | Dallas, TX 75244 | Oil & Gas Operator | Jan 2015 |
| 12263 | Harding Exploration, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2016 |
| 12264 | Harding Well Service Co. | Coahoma, TX 79511 | Oil & Gas Operator | Aug 2003 |
| 12265 | Hardrock Oil Company | Great Falls, MT 59403 | Gas Operator | Mar 2026 |
| 12266 | Hardrock Operating Company, Inc. | Fort Worth, TX 76161 | Oil & Gas Operator | Jun 2026 |
| 12267 | Hardrock Resources Inc. | Winters, TX 79567 | Oil & Gas Operator | Jun 2026 |
| 12268 | Hardway Prod & Operating, LLC | Abilene, TX 79608 | Oil & Gas Operator | Aug 2016 |
| 12269 | Hardwick Oil Company | Sugar Land, TX 77478 | Oil & Gas Operator | Nov 2014 |
| 12270 | Hardwick, Ross H. Oil Company | Devine, TX 78016 | Oil & Gas Operator | Jun 2026 |
| 12271 | Hardy And Hardy Consulting LLC | | Oil & Gas Operator | Mar 2026 |
| 12272 | Hardy Oil & Gas USA Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1996 |
| 12273 | Hardy Ranch, Inc. | Henderson, TX 75654 | Oil & Gas Operator | Jun 2026 |
| 12274 | Hardy Salt Co. | | Oil & Gas Operator | Apr 1986 |
| 12275 | Hargraves Daughters | | Oil Operator | Mar 1992 |
| 12276 | Hargraves Elston | Ponca City, OK 74604 | Oil & Gas Operator | Jul 2003 |
| 12277 | Hargraves Production, LLC | | Oil Operator | Jan 2025 |
| 12278 | Hargus Curtis | Macomb, OK 74852-8508 | Oil Operator | May 2017 |
| 12279 | Hargus Irrevocable Trust | Tecumseh, OK 74873-0590 | Oil Operator | Apr 2014 |
| 12280 | Haring Energy Company | Tuleta, TX 78162 | Oil & Gas Operator | Mar 2003 |
| 12281 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 12282 | Harken Southwest Corp | Dallas, TX 752612007 | Oil & Gas Operator | Feb 2001 |
| 12283 | Harkey Energy Inc. | Odessa, TX 79762 | Oil & Gas Operator | Feb 2020 |
| 12284 | Harkins & Co. | | Oil & Gas Operator | Oct 1986 |
| 12285 | Harkins And Co., Et Al | | Oil & Gas Operator | Dec 1980 |
| 12286 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Jun 2026 |
| 12287 | Harley Drilling & Producing LTD | Burbank, OH 44214 | Oil & Gas Operator | Dec 2025 |
| 12288 | Harlo Oil Compan | | Oil Operator | Dec 1994 |
| 12289 | Harlow Corporation, The | Amarillo, TX 79101 | Oil & Gas Operator | Apr 2014 |
| 12290 | Harlow Enterprises LLC | Artesia, NM 88210 | Oil & Gas Operator | Apr 2026 |
| 12291 | Harman Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2007 |
| 12292 | Harmel And Shawver Oil LLC | Wichita Falls, TX 76310 | Oil Operator | Jun 2026 |
| 12293 | Harmon O G LLC | Graysville, OH 45734 | Oil & Gas Operator | Dec 2025 |
| 12294 | Harmon, C. E. Oil, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2019 |
| 12295 | Harmonia Petroleum Corporation | Missouri City, TX 77459 | Oil & Gas Operator | May 2017 |
| 12296 | Harmons Well Service | Graysville, OH 45734 | Oil & Gas Operator | Dec 2019 |
| 12297 | Harmony Drilling Company, Inc. | Denver, CO 80222 | Oil & Gas Operator | Nov 2016 |
| 12298 | Harmony Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Jun 2026 |
| 12299 | Harmony Oil & Gas Co Inc | Reno, NV 89509 | Oil Operator | Dec 1994 |
| 12300 | Harmony Producing Co Inc | | Oil & Gas Operator | Dec 1995 |