| 101 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 102 | Hallwood Petroleum, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jan 2010 |
| 103 | Halo Energy L.L.C. | Kilgore, TX 75662 | Oil Operator | Oct 2025 |
| 104 | Halvey Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Oct 2004 |
| 105 | Halvey Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 106 | Ham Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Feb 2000 |
| 107 | Hamill Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1999 |
| 108 | Hamill, Claud B. Estate Of | Houston, TX 77002 | Oil & Gas Operator | Nov 1995 |
| 109 | Hamill, Flora Oil Co. | Levelland, TX 79336 | Oil & Gas Operator | Oct 2025 |
| 110 | Hamilton Brothers | Plainview, TX 79073 | Oil & Gas Operator | Mar 2008 |
| 111 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 112 | Hamilton, Clay | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Oct 2025 |
| 113 | Hamilton, J. R. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Oct 2025 |
| 114 | Hamilton, John M. | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2001 |
| 115 | Hamilton, W. B., Estate | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2004 |
| 116 | Hamilton-Tedford Oper. Co., LLC | Wichita Falls, TX 76301 | Oil Operator | May 2007 |
| 117 | Hamm, Richard | Monahans, TX 79756 | Oil & Gas Operator | Mar 1994 |
| 118 | Hamm, Richard Inc. | Monahans, TX 79756 | Oil & Gas Operator | Oct 2025 |
| 119 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Oct 2025 |
| 120 | Hamman, Blake | Graham, TX 76450 | Oil & Gas Operator | Jul 2020 |
| 121 | Hammer Oil Company | Post, TX 79356 | Oil & Gas Operator | Jun 2002 |
| 122 | Hammon Properties | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 1996 |
| 123 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 124 | Hampton Oil & Gas | Early, TX 76802 | Gas Operator | Feb 2012 |
| 125 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 126 | Hampton, Jno. W. & Son | Wichita Falls, TX 76302 | Oil & Gas Operator | Nov 1998 |
| 127 | Hanaco Operating | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 128 | Hanaco, LLC | Holliday, TX 76366 | Oil Operator | Dec 2017 |
| 129 | Hane Operating, Inc. | Santa Anna, TX 76878 | Oil & Gas Operator | Sep 2005 |
| 130 | Hanger Oil, L.L.C. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 131 | Hank Oil & Gas, Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2023 |
| 132 | Hankamer, Curtis Corporation,The | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 133 | Hankey Oil Company | Houston, TX 77027 | Oil & Gas Operator | Feb 2010 |
| 134 | Hankey Operating, Inc. | Houston, TX 77027 | Oil & Gas Operator | Mar 2016 |
| 135 | Hanks, Christopher Glenn | Gainesville, TX 76240 | Oil & Gas Operator | Oct 2025 |
| 136 | Hanley Petroleum Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 137 | Hanna Oil And Gas Company | Fort Smith, AR 72901 | Oil & Gas Operator | Jun 2025 |
| 138 | Hannathon Petroleum II, LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 139 | Hannathon Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 140 | Hannis Operating, LLC | Olney, TX 76374 | Oil & Gas Operator | Oct 2025 |
| 141 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 142 | Hanshu Production Company | Darrouzett, TX 79024 | Oil & Gas Operator | Apr 2017 |
| 143 | Hanshu Production Company, LLC | Nashville, TN 37215 | Gas Operator | Oct 2025 |
| 144 | Hanson Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 145 | Hanson Minerals Co. | Houston, TX 77042 | Oil & Gas Operator | Oct 1993 |
| 146 | Hanson Operating Company Inc | Roswell, NM 88202 | Oil & Gas Operator | Jul 2025 |
| 147 | Hanson Production Company | Cuero, TX 77954 | Oil & Gas Operator | Jul 2009 |
| 148 | Hanvey Production Co., Inc. | Roanoke, TX 76262 | Oil & Gas Operator | Nov 2012 |
| 149 | Hanvey, Don H. Oil Interests Inc | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 150 | Harbor Petroleum, LLC | Granbury, TX 76049 | Oil & Gas Operator | Oct 2025 |
| 151 | Harbor Resources LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Oct 2025 |
| 152 | Harco Land, Inc. | Dallas, TX 75230 | Oil & Gas Operator | Aug 1996 |
| 153 | Hardey Co., The | Shreveport, LA 71107 | Oil & Gas Operator | Oct 2025 |
| 154 | Hardin Energy Co., Inc. | Bigfoot, TX 78005 | Oil Operator | Oct 2025 |
| 155 | Hardin, W.V. Estate | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2002 |
| 156 | Harding Company | Dallas, TX 75244 | Oil & Gas Operator | Jan 2015 |
| 157 | Harding Exploration, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2016 |
| 158 | Harding Well Service Co. | Coahoma, TX 79511 | Oil & Gas Operator | Aug 2003 |
| 159 | Hardrock Operating Company, Inc. | Fort Worth, TX 76161 | Oil & Gas Operator | Oct 2025 |
| 160 | Hardrock Resources Inc. | Winters, TX 79567 | Oil & Gas Operator | Oct 2025 |
| 161 | Hardway Prod & Operating, LLC | Abilene, TX 79608 | Oil & Gas Operator | Aug 2016 |
| 162 | Hardwick Oil Company | Sugar Land, TX 77478 | Oil & Gas Operator | Nov 2014 |
| 163 | Hardwick, Mark P. Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 1994 |
| 164 | Hardwick, Ross H. Oil Company | Devine, TX 78016 | Oil & Gas Operator | Oct 2025 |
| 165 | Hardy Oil & Gas USA Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1996 |
| 166 | Hardy Ranch, Inc. | Henderson, TX 75654 | Oil & Gas Operator | Oct 2025 |
| 167 | Hargis Exploration & Prod., Inc. | Weatherford, TX 76086 | Oil & Gas Operator | Jul 1996 |
| 168 | Haring Energy Company | Tuleta, TX 78162 | Oil & Gas Operator | Mar 2003 |
| 169 | Harken Exploration Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2008 |
| 170 | Harkey Energy Inc. | Odessa, TX 79762 | Oil & Gas Operator | Feb 2020 |
| 171 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Oct 2025 |
| 172 | Harlow Corporation, The | Amarillo, TX 79101 | Oil & Gas Operator | Apr 2014 |
| 173 | Harman Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Dec 2007 |
| 174 | Harmel And Shawver Oil LLC | Wichita Falls, TX 76310 | Oil Operator | Oct 2025 |
| 175 | Harmon, C. E. Oil, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Oct 2019 |
| 176 | Harmonia Petroleum Corporation | Missouri City, TX 77459 | Oil & Gas Operator | May 2017 |
| 177 | Harmony Drilling Company, Inc. | Denver, CO 80222 | Oil & Gas Operator | Nov 2016 |
| 178 | Harmony Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Oct 2025 |
| 179 | Harms, Vance N. | Talpa, TX 76882 | Oil & Gas Operator | Mar 2016 |
| 180 | Harper Hefte, Inc. | Corpus Chrsti, TX 78410 | Oil & Gas Operator | Oct 2025 |
| 181 | Harper Oil And Gas, LLC | Pratt, KS 67124 | Oil & Gas Operator | Jun 2025 |
| 182 | Harper Production, LLC | Spearman, TX 79081 | Oil & Gas Operator | Oct 2025 |
| 183 | Harper, Clint | Woodson, TX 76491 | Oil & Gas Operator | Oct 2025 |
| 184 | Harper, Wayne | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 185 | Harper, William E. | Woodson, TX 76491 | Oil & Gas Operator | Jul 2016 |
| 186 | Harrell Operating Inc | Graham, TX 76450 | Oil & Gas Operator | Sep 2005 |
| 187 | Harrell Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Jun 2008 |
| 188 | Harrell, Charles | Graham, TX 76450 | Oil & Gas Operator | Dec 2000 |
| 189 | Harrier Holdings, LTD. | Burnet, TX 78611 | Oil Operator | Oct 2025 |
| 190 | Harrigan Energy Partners, Inc. | Houston, TX 77058 | Oil & Gas Operator | Sep 2010 |
| 191 | Harrigan Operating, LLC | Houston, TX 77258 | Oil & Gas Operator | Apr 2020 |
| 192 | Harris Energy Partners Op, LLC | Fort Worth, TX 76116 | Oil Operator | Oct 2025 |
| 193 | Harris Energy Services, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 194 | Harris Oil & Gas Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2016 |
| 195 | Harris, Jake, Trustee | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 2001 |
| 196 | Harris, Sam E. | Albany, TX 76430 | Oil & Gas Operator | Aug 2003 |
| 197 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 198 | Harrison Oil & Gas Inc | Houston, TX 77019 | Oil & Gas Operator | Jun 2025 |
| 199 | Harrison, Dan J III&Bruce F Est | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 200 | Harrison, Dan J. III&Bruce F. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |