| 101 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2026 |
| 102 | Coleman Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Jan 2023 |
| 103 | Coltrane Charles | | Oil Operator | Dec 1980 |
| 104 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 105 | Columbus Production Inc | | Oil & Gas Operator | Mar 2005 |
| 106 | Comdisco Exploration Inc | | Oil Operator | Dec 1990 |
| 107 | Comet Energy Services LLC | Traverse City, MI 49686 | Oil & Gas Operator | Oct 2011 |
| 108 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 109 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 110 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 111 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Jul 2026 |
| 112 | Continental Industries LC | Casper, WY 82602 | Oil & Gas Operator | Feb 2008 |
| 113 | Continental Production Co LLC | Greenwood VIllage, CO 80155 | Oil & Gas Operator | Aug 2012 |
| 114 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Sep 2026 |
| 115 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 116 | Cook D L | Holliday, TX 76366 | Oil & Gas Operator | Dec 2008 |
| 117 | Coquina Oil Corporation | Houston, TX 77227 | Oil & Gas Operator | Mar 2015 |
| 118 | Coral Production Corporation | Denver, CO 80201 | Oil & Gas Operator | Apr 2026 |
| 119 | Cordero Mining Co | Gillette, WY 82717 | Oil Operator | Nov 2009 |
| 120 | Cordero Oil And Gas LLC | Gillette, WY 82716 | Oil Operator | Nov 2021 |
| 121 | Corrida Oil Inc | Denver, CO 80217 | Oil & Gas Operator | Jun 1990 |
| 122 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 123 | Cotton Petroleum Corporation | Tulsa, OK 74102 | Oil & Gas Operator | Jan 2005 |
| 124 | Cowboy Clean Fuels LLC | Laramie, WY 82072 | Gas Operator | Jun 2026 |
| 125 | Cox Edwin L & Berry R | | Oil & Gas Operator | Oct 1987 |
| 126 | Cox Kendall Jay | Recluse, WY 28775 | Oil & Gas Operator | Aug 2016 |
| 127 | Cramer Oil Company | Denver, CO 80202 | Oil Operator | Aug 2012 |
| 128 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2026 |
| 129 | Creek Oil Company | Colorado Springs, CO 80906 | Oil & Gas Operator | Aug 2001 |
| 130 | Crest Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2026 |
| 131 | Crystal Exploration & Production Company | Shreveport, LA 71120 | Oil & Gas Operator | Feb 1995 |
| 132 | Crystal Oil Company | Shreveport, LA 71120 | Oil & Gas Operator | Jul 1995 |
| 133 | Czar Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Oct 1992 |
| 134 | D K Cook Heirs LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2011 |
| 135 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Sep 2026 |
| 136 | Dalen Resources Oil & Gas Co | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 137 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 138 | Daube Company The | Ardmore, OK 73401 | Oil & Gas Operator | Jul 2026 |
| 139 | Davey Corporation | Golden, CO 80401 | Oil & Gas Operator | Jul 2026 |
| 140 | Davis Exploration | | Oil Operator | Dec 2007 |
| 141 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 142 | DCD Inc | Gillette, WY 82716 | Oil & Gas Operator | Aug 2003 |
| 143 | Deca Energy Corporation | | Oil & Gas Operator | Aug 1986 |
| 144 | Decalta International Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2015 |
| 145 | Dekalb Energy Company | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 1996 |
| 146 | Denbury Onshore, LLC | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 147 | Devon Energy Operating Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2013 |
| 148 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2026 |
| 149 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 150 | Diamond Oil & Gas LLC | Casper, WY 82604 | Oil & Gas Operator | Jul 2026 |
| 151 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 152 | Dietrich Resources Corporation | | Oil & Gas Operator | Jun 2007 |
| 153 | DKM Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Sep 2011 |
| 154 | DNR Oil And Gas, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Jul 2026 |
| 155 | Dol Resources Inc | Rowlett, TX 75088 | Oil & Gas Operator | Aug 2026 |
| 156 | Dome Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 157 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 158 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 159 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 160 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 161 | E & B Natural Resources Management | Guilderland Centek, NY 12085 | Oil & Gas Operator | Jul 2026 |
| 162 | Eason Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2012 |
| 163 | Eastern American Energy Corp | | Oil & Gas Operator | Dec 2008 |
| 164 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 165 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Jun 2026 |
| 166 | Ellbogen John P LTD | Casper, WY 82602 | Oil & Gas Operator | Jul 2026 |
| 167 | Emc Energy | | Oil & Gas Operator | Jun 1985 |
| 168 | Emep II Operating LLC | | Oil & Gas Operator | Jun 2026 |
| 169 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Jun 2026 |
| 170 | Emerald Restoration & Prod | Gillette, WY 82718 | Oil & Gas Operator | Jul 2000 |
| 171 | Encana Energy Resources Inc | Denver, CO 80202-2828 | Oil & Gas Operator | May 2026 |
| 172 | Energen Resources Maq Inc | Birmingham, AL 35203 | Oil & Gas Operator | Sep 2000 |
| 173 | Energetics Inc | Englewood, CO 80155 | Oil & Gas Operator | Aug 1985 |
| 174 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Jun 2026 |
| 175 | Energy Operating Company Inc | Lakewood, CO 80235 | Oil & Gas Operator | Dec 2012 |
| 176 | Enpro LLC | Cottonwood, UT 84047 | Oil & Gas Operator | Nov 2017 |
| 177 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 178 | EOG Y Resources Inc | Artesia, NM 88210 | Oil & Gas Operator | Feb 2019 |
| 179 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 180 | Equitable Resources Energy Company | Big Stone Gap, VA 24219 | Oil & Gas Operator | Dec 1997 |
| 181 | Equity Oil Company | Salt Lake City, UT 84110-095 | Oil & Gas Operator | Aug 2004 |
| 182 | Escalera Resources Co | Casper, WY 82602 | Oil & Gas Operator | May 2018 |
| 183 | Evergreen Operating Company | Denver, CO 80202 | Oil & Gas Operator | Apr 1996 |
| 184 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | May 2026 |
| 185 | Exeter Drilling Company | Denver, CO 80217 | Oil & Gas Operator | Sep 1997 |
| 186 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 187 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Jun 2026 |
| 188 | Family Tree Corporation | Lakewood, CO 80228 | Oil & Gas Operator | Feb 2013 |
| 189 | Fancher Oil LLC | Greenwood, CO 80111 | Oil & Gas Operator | Nov 2006 |
| 190 | Faulconer, Vernon E., Inc. | Tyler, TX 75711 | Oil & Gas Operator | Jun 2026 |
| 191 | FDL Operating, LLC | Judson, TX 75660 | Oil & Gas Operator | Sep 2026 |
| 192 | Federated Oil & Gas Properties | Traverse City, MI 49685 | Gas Operator | Mar 2014 |
| 193 | Felmont Oil Corporation | Walnut Creek, CA 94596-3568 | Oil & Gas Operator | Feb 1990 |
| 194 | Ferguson Oil Company Inc | | Oil & Gas Operator | Apr 1994 |
| 195 | Fina Oil And Chemical Company | Dallas, TX 75221 | Oil & Gas Operator | May 2019 |
| 196 | First Energy Corporation | | Oil & Gas Operator | Jun 1993 |
| 197 | First Sourcenergy Wyoming Inc | Gillette, WY 82718 | Gas Operator | Jul 2003 |
| 198 | Flag-Redfern Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Jul 2002 |
| 199 | Flahive Oil & Gas LLC | Golden, CO 80401 | Oil Operator | Oct 1995 |
| 200 | Florida Gas Exploration Co | | Oil & Gas Operator | Feb 1985 |