| 101 | Hondo Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Oct 1995 |
| 102 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 103 | HR Energy LLC | Shelby, MT 59474 | Oil & Gas Operator | Sep 2025 |
| 104 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Sep 2002 |
| 105 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Dec 2025 |
| 106 | Hudson Group LLC | Casper, WY 82601 | Oil & Gas Operator | Jul 2025 |
| 107 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 108 | Husky Oil Company | Cody, WY 82414 | Oil & Gas Operator | Dec 1984 |
| 109 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 110 | Inland Production Company | Vernal, UT 84079 | Oil & Gas Operator | Dec 2004 |
| 111 | Interline Resources Corp | Casper, WY 82601 | Oil & Gas Operator | Oct 2009 |
| 112 | Internorth Inc | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2014 |
| 113 | Itr Petroleum Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 114 | K N Energy Inc | Lakewood, CO 80228 | Oil & Gas Operator | Nov 2000 |
| 115 | Kaiser Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1990 |
| 116 | Kaneb Oil & Gas | | Oil & Gas Operator | Oct 1987 |
| 117 | KCS Mountain Resources Inc | Manderson, WY 82432 | Oil & Gas Operator | Nov 2006 |
| 118 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Oct 2025 |
| 119 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Oct 2025 |
| 120 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 121 | Kobar Corporation | Riverton, WY 82501 | Gas Operator | Dec 1996 |
| 122 | Koch Exploration Company | Houston, TX 77046 | Oil & Gas Operator | Apr 2003 |
| 123 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2025 |
| 124 | L B Industries Inc | Englewood, CO 80112 | Oil & Gas Operator | Jun 2003 |
| 125 | Laguna Petroleum Company | Casper, WY 82601 | Oil & Gas Operator | Dec 1982 |
| 126 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Dec 2025 |
| 127 | Llosu Corporation | Rawlins, WY 82301 | Oil & Gas Operator | Mar 2002 |
| 128 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 129 | Mapco Oil Company | | Oil & Gas Operator | Jan 1985 |
| 130 | Mar/Reg Investments | Irving, TX 75016 | Oil & Gas Operator | Jul 1999 |
| 131 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 132 | Martens & Peck Production Co | Denver, CO 80222 | Oil & Gas Operator | Feb 1997 |
| 133 | Martin Exploration | Westminster, CO 80030 | Oil & Gas Operator | Dec 1993 |
| 134 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Oct 2025 |
| 135 | McCartney Engineering LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Oct 2025 |
| 136 | Meerkat Logistics And Operations LLC | Tuscaloosa, AL 35401 | Oil Operator | Oct 2025 |
| 137 | Mels Water Service Inc | Lysite, WY 82642 | Oil Operator | Mar 2013 |
| 138 | Memorial Exploration Company | Saint Louis, MO 63105 | Oil & Gas Operator | Aug 1996 |
| 139 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 140 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 141 | Meritage Energy Partners LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 142 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Oct 2025 |
| 143 | Michigan-Wisconsin Pipe Line Co | | Oil & Gas Operator | Dec 1983 |
| 144 | Mobil Expl & Producing North America Inc | | Oil & Gas Operator | Nov 1986 |
| 145 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 146 | Monsanto Company | Indianapolis, IN 46280 | Oil & Gas Operator | Jan 2005 |
| 147 | Montex Drilling Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 148 | Monument Global Resources Inc | Dallas, TX 75243 | Oil & Gas Operator | Jan 2025 |
| 149 | Morsey Oil & Gas Corporation | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2025 |
| 150 | Mosbacher Production Co. | Houston, TX 77001 | Oil & Gas Operator | Aug 1984 |
| 151 | Mountain Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Apr 2013 |
| 152 | MRD Operating LLC (Delaware) | Houston, TX 77010 | Oil & Gas Operator | Jul 2015 |
| 153 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 154 | Natural Gas Processing Company | Worland, WY 82401 | Oil & Gas Operator | Oct 2025 |
| 155 | Newfield Production Company | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jul 2022 |
| 156 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 157 | Nortex Gas & Oil Co | Tulsa, OK 74135 | Oil & Gas Operator | Sep 1993 |
| 158 | North American Energy | | Oil & Gas Operator | Feb 1986 |
| 159 | Northstar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 160 | Northwest Exploration | | Oil & Gas Operator | Dec 1984 |
| 161 | Nova Energy Inc | Casper, WY 82601 | Oil & Gas Operator | Oct 2020 |
| 162 | Nova Petroleum Cororation | | Oil & Gas Operator | Mar 1987 |
| 163 | Oilfield Consultants | | Oil & Gas Operator | Dec 1987 |
| 164 | Omimex Petroleum Inc (Co) | Newcastle, WY 82701 | Oil & Gas Operator | May 2001 |
| 165 | Omni Operating Company | Osage, WY 82723 | Oil & Gas Operator | Sep 2001 |
| 166 | Oneida Energy Corporation | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2003 |
| 167 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 168 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 169 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 170 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 171 | PDS Resources LLC | | Oil & Gas Operator | Oct 2025 |
| 172 | Pendragon Energy Partners Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2009 |
| 173 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 174 | Petroleum Resource Management Corp | Denver, CO 80203 | Oil & Gas Operator | Oct 2025 |
| 175 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 176 | Phoenix Production Company | Cody, WY 82414-3607 | Oil & Gas Operator | Oct 2023 |
| 177 | Pioneer Oil & Gas | South Jordan, UT 84095 | Oil & Gas Operator | Jan 2014 |
| 178 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 179 | Prenalta Corporation | Terrytown, NY 10591 | Oil & Gas Operator | Jan 1997 |
| 180 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 181 | Purewest Resources Inc | Pinedale, WY 82941 | Oil & Gas Operator | Sep 2025 |
| 182 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 183 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 184 | Quinoco Petroleum Inc | | Oil & Gas Operator | Dec 1990 |
| 185 | Rathpro Inc | Douglas, WY 82633 | Oil & Gas Operator | Feb 1994 |
| 186 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Nov 2025 |
| 187 | Saba Energy Of Texas Inc | Houston, TX 77042 | Oil & Gas Operator | Jul 2007 |
| 188 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Dec 2025 |
| 189 | Salt Creek Operating LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2020 |
| 190 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 191 | Samson Resources Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |
| 192 | Sauer Bill Oil & Gas Company LLC | Casper, WY 82604 | Oil & Gas Operator | Jun 1999 |
| 193 | Sayers Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2005 |
| 194 | Slaughter J M Oil Company | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2001 |
| 195 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Dec 2025 |
| 196 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 197 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 198 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 199 | St Oil Company | Denver, CO 80264-2101 | Oil & Gas Operator | Dec 2010 |
| 200 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |