| 101 | Florida Gas Exploration Co | | Oil & Gas Operator | Feb 1985 |
| 102 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 103 | Forcenergy Inc | Miami, FL 33129 | Oil & Gas Operator | Mar 2015 |
| 104 | Fossil Energy Inc | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 105 | General Atlantic Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 106 | Glenmar Company | Monterey, CO 93940 | Oil Operator | Oct 1998 |
| 107 | GLG Energy LP | Austin, TX 78701 | Oil & Gas Operator | Jun 1994 |
| 108 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 109 | Green Reserve Energy Holdings LLC | Houston, TX 77077 | Oil & Gas Operator | Aug 2025 |
| 110 | Griffiths Oil LLC | Edgerton, WY 82635 | Oil Operator | Aug 2025 |
| 111 | Grizzly Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2025 |
| 112 | Grynberg, Jack J. | Denver, CO 80237 | Oil & Gas Operator | Jun 2021 |
| 113 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 114 | Hamon Jake L | Dallas, TX 75201-3902 | Oil & Gas Operator | Nov 1997 |
| 115 | Harpel John P Jr | FT. Collins, CO 80525 | Oil & Gas Operator | May 1998 |
| 116 | Harper Oil Co. | Denver, CO 80217 | Oil & Gas Operator | Jun 2025 |
| 117 | Hawks Company | Casper, WY 82602 | Oil & Gas Operator | Apr 2007 |
| 118 | Hershey Oil Corporation | | Oil & Gas Operator | Jul 1992 |
| 119 | High Summit Oil & Gas Inc | | Oil & Gas Operator | Sep 1987 |
| 120 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Oct 2025 |
| 121 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 122 | Hondo Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Oct 1995 |
| 123 | Hot Springs Resources LTD | Casper, WY 82601 | Oil Operator | Dec 2014 |
| 124 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 125 | HRM Resources II, LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 126 | HRM Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2015 |
| 127 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 128 | Hurley Oil Company | | Oil Operator | Dec 1988 |
| 129 | Integrity Oil & Gas | Golden, CO 80401 | Oil & Gas Operator | May 2011 |
| 130 | Intercoast Oil And Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Jun 1997 |
| 131 | Intoil, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Dec 2002 |
| 132 | Iron Creek Properties Inc | Casper, WY 82604 | Oil & Gas Operator | Jul 2025 |
| 133 | JN Exploration & Production | Billings, MT 59103-0159 | Oil & Gas Operator | Apr 2001 |
| 134 | Jogruss Oil Corporation | | Oil & Gas Operator | Jul 1991 |
| 135 | K & W Oil Company | MT Carmel, IL 62830 | Oil & Gas Operator | May 2013 |
| 136 | Kachina Exploration Inc | Cheyenne, WY 82003 | Oil & Gas Operator | Jul 2000 |
| 137 | Katherman Vance E | Casper, WY 82601 | Oil Operator | Dec 2004 |
| 138 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 139 | KCS Mountain Resources Inc | Manderson, WY 82432 | Oil & Gas Operator | Nov 2006 |
| 140 | Kem Ventures, LP | Katy, TX 77450 | Oil & Gas Operator | Jul 2025 |
| 141 | Kennedy Oil | Gillette, WY 82716 | Oil & Gas Operator | Aug 2025 |
| 142 | Kentta & Drwenski | Casper, WY 82602 | Oil & Gas Operator | Nov 1995 |
| 143 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 144 | Kewanee Oil Company | Houston, TX 77001 | Oil & Gas Operator | Aug 1978 |
| 145 | Kinder Morgan Inc | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2011 |
| 146 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 147 | Klabzuba Oil & Gas Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2012 |
| 148 | L & J Operating Inc | Gillette, WY 82718 | Oil & Gas Operator | Aug 2016 |
| 149 | L R Company | Casper, WY 82602 | Oil & Gas Operator | Sep 2007 |
| 150 | Lance Oil & Gas Company Inc | Kirtland, NM 87417 | Oil & Gas Operator | Mar 2013 |
| 151 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Oct 2025 |
| 152 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Oct 2025 |
| 153 | Loco | Casper, WY 82602 | Oil & Gas Operator | Jul 2022 |
| 154 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 155 | M-3 Industries | Casper, WY 82602 | Oil & Gas Operator | Jun 2025 |
| 156 | M2S Oil LLC | | Oil Operator | Jun 2025 |
| 157 | Macum Energy Inc | Billings, MT 59104 | Oil & Gas Operator | Aug 2021 |
| 158 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 159 | Manx Oil Corporation | Casper, WY 82601 | Oil & Gas Operator | Jun 2010 |
| 160 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 161 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Aug 2025 |
| 162 | McAdams Roux & Associates | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 163 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 164 | McMurry Oil LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 165 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 166 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 167 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 168 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 169 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 170 | Meritage Energy Partners LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 171 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Aug 2025 |
| 172 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2025 |
| 173 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 174 | Mineral Resources & Engineering | Aladdin, WY 82710 | Oil Operator | Jul 1991 |
| 175 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2025 |
| 176 | Monsanto Company | Indianapolis, IN 46280 | Oil & Gas Operator | Jan 2005 |
| 177 | Mosbacher Production Co. | Houston, TX 77001 | Oil & Gas Operator | Aug 1984 |
| 178 | MRD Operating LLC (Delaware) | Houston, TX 77010 | Oil & Gas Operator | Jul 2015 |
| 179 | Mustang Resources LLC | Houston, TX 77256 | Oil & Gas Operator | Aug 2025 |
| 180 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 181 | Mystique Developments | Denver, CO 80202 | Oil & Gas Operator | Dec 1997 |
| 182 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 183 | Natrona County Holdings LLC | Austin, TX 78701 | Oil & Gas Operator | Nov 2020 |
| 184 | Natural Gas Processing Company | Worland, WY 82401 | Oil & Gas Operator | Aug 2025 |
| 185 | Nautilus Exploration LLC | Denver, CO 80218 | Oil Operator | Mar 2011 |
| 186 | Nella Company LTD | | Oil Operator | Dec 1986 |
| 187 | New Era Oil/Preferred Energy | | Oil & Gas Operator | Sep 1993 |
| 188 | New Horizon Resources LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 189 | Neward Corporation | FT. Worth, TX 76102 | Oil & Gas Operator | Dec 1997 |
| 190 | Newman Bros Drilling | | Oil & Gas Operator | Apr 2004 |
| 191 | Newton Steve Drilling | Worland, WY 82401 | Oil Operator | Apr 2001 |
| 192 | Nicolaysen G G Jr | | Oil & Gas Operator | Dec 1995 |
| 193 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 194 | North Finn LLC | Casper, WY 82605 | Oil & Gas Operator | Aug 2025 |
| 195 | Nucor Oil & Gas Inc | Riverton, WY 82501 | Oil & Gas Operator | Jul 2025 |
| 196 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 197 | Oil Mountain Energy Inc | Casper, WY 82609 | Oil Operator | Aug 2025 |
| 198 | Oilfield Salvage & Service Company | Littleton, CO 80120 | Oil & Gas Operator | Aug 2025 |
| 199 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 200 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |