| 101 | Chermac Energy Corporation | Edmond, OK 73083 | Oil & Gas Operator | Apr 2020 |
| 102 | Cherokee Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 103 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2025 |
| 104 | Chieftain Oil Co Inc | Kiowa, KS 67070 | Oil & Gas Operator | Oct 2025 |
| 105 | Chisholm Oil And Gas Operating LLC | Tulsa, OK 74103-3522 | Oil & Gas Operator | Oct 2025 |
| 106 | Chisholm Trail Resources Inc | Hennessey, OK 73742 | Oil & Gas Operator | Nov 2002 |
| 107 | Cimarron Operating Company | Oklahoma City, OK 73112-3967 | Oil & Gas Operator | May 2011 |
| 108 | Citizen Energy III LLC | Devner, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 109 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Mar 2020 |
| 110 | Clay A Muegge | | Oil & Gas Operator | Oct 2025 |
| 111 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 112 | Clifford Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Jul 2015 |
| 113 | CLV Oil & Gas Inc | Tulsa, OK 74169-0713 | Oil & Gas Operator | Apr 2020 |
| 114 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 115 | Co-St Oil Operating Co Inc | Enid, OK 73706 | Oil & Gas Operator | Apr 1997 |
| 116 | COG Petroleum Corporation | Oklahoma City, OK 73116-7326 | Oil & Gas Operator | Mar 2019 |
| 117 | Collet Oil Ventures Inc | Denver, CO 80217 | Oil & Gas Operator | Jun 2004 |
| 118 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 119 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Dec 2025 |
| 120 | Compass Drilling Inc | Enid, OK 73702-5467 | Oil & Gas Operator | Sep 2014 |
| 121 | Compass Resources | Enid, OK 73702 | Oil & Gas Operator | Dec 2007 |
| 122 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 123 | Confed Oil Incorporated | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 124 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |
| 125 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 126 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 127 | Continental Gas Inc | Enid, OK 73702-5103 | Oil & Gas Operator | Apr 2012 |
| 128 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Dec 2025 |
| 129 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 130 | Coterra Energy Operating Co. | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 131 | Cox Gas Corporation | Dallas, TX 75201-7306 | Oil & Gas Operator | Apr 2015 |
| 132 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 133 | Cross Timbers Oil Company | Dallas, TX 75284 | Oil & Gas Operator | May 2013 |
| 134 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2025 |
| 135 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 136 | Crown Central Pet Corp | Bellaire, TX 77401 | Oil & Gas Operator | Dec 2016 |
| 137 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Sep 2025 |
| 138 | Crusader Energy Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2011 |
| 139 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 140 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 141 | Crusader Energy II LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2015 |
| 142 | Crusader Energy III LLC | Oklahoma City, OK 73142-1856 | Oil & Gas Operator | Feb 2011 |
| 143 | Crystal Energy Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Feb 2019 |
| 144 | Culebra Oil & Gas, LLC | Kerrville, TX 78028 | Oil & Gas Operator | Dec 2025 |
| 145 | Curzon Operating Company LTD | Oklahoma City, OK 73118-4821 | Oil & Gas Operator | Oct 2025 |
| 146 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 147 | D & D Pipe & Equipment Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Mar 2005 |
| 148 | D & G Oil & Gas Company Inc | Enid, OK 73702-2027 | Oil & Gas Operator | Nov 2021 |
| 149 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Dec 2025 |
| 150 | D & J Oil Company Of Okla Inc | Enid, OK 73706-0129 | Oil & Gas Operator | May 1999 |
| 151 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 152 | Dab And Associates Inc | Crescent, OK 73028-0580 | Oil & Gas Operator | Nov 2014 |
| 153 | Dar-Lon Operating Company | Lamont, OK 74643 | Oil & Gas Operator | Oct 2000 |
| 154 | Darling Dan Oil | | Oil & Gas Operator | Sep 2018 |
| 155 | Darling Oil Corporation | Lamont, OK 74643 | Oil & Gas Operator | Oct 2025 |
| 156 | Darrah Oil Company, LLC | Wichita, KS 67201 | Oil & Gas Operator | Dec 2025 |
| 157 | Dart Oil Properties | Enid, OK 73703 | Oil & Gas Operator | Oct 1992 |
| 158 | Davco Productions Inc | Springer, OK 73458-8191 | Oil & Gas Operator | Jun 2021 |
| 159 | David E Morgan Inc | Danville, CA 94506-2035 | Oil & Gas Operator | Oct 2025 |
| 160 | Davis Operating Company | Elysian Field, TX 75642 | Oil & Gas Operator | Dec 2025 |
| 161 | Davis, William H. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2014 |
| 162 | Davon Drilling Company | Oklahoma City, OK 73113-0665 | Oil & Gas Operator | Mar 2015 |
| 163 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 164 | Deck Oil Company | Tulsa, OK 74101 | Oil & Gas Operator | Jun 2020 |
| 165 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 166 | Dem Operations Inc | Lamont, OK 74643-5010 | Oil & Gas Operator | Oct 2025 |
| 167 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 168 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 169 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 170 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 171 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Dec 2025 |
| 172 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Dec 2025 |
| 173 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Jun 2025 |
| 174 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 175 | Dorchester Resources LP | Oklahoma City, OK 73154-8879 | Oil & Gas Operator | Aug 2021 |
| 176 | Douglass Dietz & Daley Inc | Oklahoma City, OK 73154-0125 | Oil & Gas Operator | Aug 2023 |
| 177 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 178 | Drake Exploration Inc | Tulsa, OK 74105-4250 | Oil & Gas Operator | Oct 2025 |
| 179 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 180 | Dune Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jan 1993 |
| 181 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 182 | Eagle Creek Resources, LLC | Sewickley, PA 15143 | Oil & Gas Operator | Dec 2024 |
| 183 | Eagle Energy Production LLC | Tulsa, OK 74136-1935 | Oil & Gas Operator | Mar 2020 |
| 184 | Eagle Exploration Production LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 185 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Sep 2025 |
| 186 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Oct 2025 |
| 187 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 188 | Edinger Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2007 |
| 189 | Eec Inc | Norman, OK 73069-6344 | Oil & Gas Operator | Oct 2025 |
| 190 | Egret Operating Company | Muskogee, OK 74401 | Oil & Gas Operator | Oct 2025 |
| 191 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 192 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Oct 2025 |
| 193 | Emc Exploration Company Inc | Oklahoma City, OK 73103-3775 | Oil & Gas Operator | Jul 2007 |
| 194 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 195 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 196 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 197 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 198 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 199 | Equal Energy Us Inc | Tulsa, OK 74103-4621 | Oil & Gas Operator | Nov 2019 |
| 200 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |