| 101 | Cheyenne Petroleum Company | Oklahoma City, OK 73134 | Oil & Gas Operator | Jul 2025 |
| 102 | Chieftain Oil Co Inc | Kiowa, KS 67070 | Oil & Gas Operator | May 2025 |
| 103 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 104 | Cimarex Energy Co. Of Colorado | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 105 | Cimarron Operating Company | Oklahoma City, OK 73112-3967 | Oil & Gas Operator | May 2011 |
| 106 | Cimarron River Operating Co | Mannford, OK 74044 | Oil & Gas Operator | Apr 2025 |
| 107 | Cirrus Production Company | Enid, OK 73702 | Oil & Gas Operator | Apr 2025 |
| 108 | Citizen Energy III LLC | Devner, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 109 | Citrus Energy Corporation | Castle Rock, CO 80104 | Oil & Gas Operator | Mar 2020 |
| 110 | Clark Exploration Co. | Highlands Ranch, CO 80126-7645 | Oil & Gas Operator | Nov 2024 |
| 111 | Cleary Exploration LLC | Oklahoma City, OK 73112-7221 | Oil & Gas Operator | Oct 2014 |
| 112 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 113 | CMS Nomeco Oil & Gas Co. | Jackson, MI 49201 | Oil & Gas Operator | Jan 2015 |
| 114 | CMX Inc Of Kansas | Wichita, KS 67206-2561 | Oil & Gas Operator | May 2025 |
| 115 | Coastal Oils Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2013 |
| 116 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 117 | Comanche Exploration Co LLC | Oklahoma City, OK 73116-7334 | Oil & Gas Operator | May 2025 |
| 118 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | May 2025 |
| 119 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2025 |
| 120 | Comstock Oil & Gas, LP | Frisco, TX 75034 | Oil & Gas Operator | Aug 2019 |
| 121 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 122 | ConocoPhillips Company | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 123 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Jul 2025 |
| 124 | Continental Gas Inc | Enid, OK 73702-5103 | Oil & Gas Operator | Apr 2012 |
| 125 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 126 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Jul 2025 |
| 127 | Cooper Operating LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2025 |
| 128 | Corman, Jack | Dallas, TX 75231 | Oil & Gas Operator | May 2022 |
| 129 | Corpening, Joe F. | Bowie, TX 76230 | Oil & Gas Operator | Oct 2013 |
| 130 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 131 | Costilla Energy Inc | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 132 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 133 | Crabtree Barbara T | Forney, TX 75126-5818 | Oil & Gas Operator | Oct 2024 |
| 134 | Crawley Petroleum Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 135 | Cross Timbers Operating Co | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 136 | Cross Timbers Production Co | Oklahoma City, OK 73102-5605 | Oil & Gas Operator | Mar 2005 |
| 137 | Crouch Petroleum Company | Amarillo, TX 79110 | Oil & Gas Operator | Mar 2015 |
| 138 | Crow Oil LLC | Tulsa, OK 74133-2914 | Oil & Gas Operator | Sep 2019 |
| 139 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Apr 2025 |
| 140 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 141 | Crusader Energy Group LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Mar 2015 |
| 142 | Crusader Energy III LLC | Oklahoma City, OK 73142-1856 | Oil & Gas Operator | Feb 2011 |
| 143 | Culebra Oil & Gas LLC | Kerrville, TX 78028 | Oil & Gas Operator | Jul 2025 |
| 144 | Cummings Oil Company | Oklahoma City, OK 73112-6113 | Oil & Gas Operator | May 2025 |
| 145 | D & B Operating LLC | Ringwood, OK 73768 | Oil Operator | Jan 2023 |
| 146 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Jul 2025 |
| 147 | D & J Oil Company Of Okla Inc | Enid, OK 73706-0129 | Oil & Gas Operator | May 1999 |
| 148 | D C Energy, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | Apr 2020 |
| 149 | Dalcor Energy LLC | Duncan, OK 73534 | Oil & Gas Operator | Apr 2025 |
| 150 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 151 | Darrah Oil Company LLC | Wichita, KS 67201 | Oil & Gas Operator | Jul 2025 |
| 152 | Davon Drilling Company | Oklahoma City, OK 73113-0665 | Oil & Gas Operator | Mar 2015 |
| 153 | Dawson Resources Inc | Franktown, CO 80116 | Oil & Gas Operator | Mar 2015 |
| 154 | Dawson, Levi S | | Oil & Gas Operator | Mar 2015 |
| 155 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Apr 2025 |
| 156 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | May 2025 |
| 157 | Delta D Operations | Wilson, OK 73463 | Oil & Gas Operator | Jul 2014 |
| 158 | Deminex U.S. Oil Company | | Oil & Gas Operator | Jan 1998 |
| 159 | Dennett'S Inc | Enid, OK 73701-1851 | Oil & Gas Operator | Apr 2014 |
| 160 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 161 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 162 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 163 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 164 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Jul 2025 |
| 165 | DLB Energy Corporation | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Dec 2014 |
| 166 | DLB Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Jul 2025 |
| 167 | DMS Oil Company | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 168 | Dolphin Energy LLC | Lake Worth, FL 33467 | Oil & Gas Operator | Mar 2025 |
| 169 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 170 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 171 | Dorado E & P Partners LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 172 | DRG Energy Inc | Norman, OK 73026-3171 | Oil & Gas Operator | Apr 2025 |
| 173 | Eagle Energy Production LLC | Tulsa, OK 74136-1935 | Oil & Gas Operator | Mar 2020 |
| 174 | Eagle Exploration Production LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 175 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Jul 2025 |
| 176 | Eagle Rock Mid-Continent Operating LLC | Tulsa, OK 74103-3703 | Oil & Gas Operator | Apr 2025 |
| 177 | Earlsboro Energies Corporation | Oklahoma City, OK 73116-3605 | Oil & Gas Operator | Apr 2025 |
| 178 | Eberly & Meade | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2002 |
| 179 | Edinger Engineering, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2025 |
| 180 | Edwards & Leach Oil Company | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2005 |
| 181 | Egan Resources Inc. | Katy, TX 77494 | Oil & Gas Operator | Oct 2016 |
| 182 | El Pache Energy Inc | Duncan, OK 73533 | Oil & Gas Operator | Aug 2017 |
| 183 | El Paso Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 184 | Elder & Vaughn Inc | Oklahoma City, OK 73154-0938 | Oil & Gas Operator | Mar 2008 |
| 185 | Elite Tank Trucks, Inc | | Oil & Gas Operator | Apr 2025 |
| 186 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 187 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 188 | Enernet Inc | Oklahoma City, OK 73102-8004 | Oil & Gas Operator | Nov 2014 |
| 189 | Enersource Royalty Corporation | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2013 |
| 190 | Enex Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 191 | Enserch Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Apr 2015 |
| 192 | Ensource Inc | Midland, TX 79705 | Oil & Gas Operator | Aug 1998 |
| 193 | EOG (Oklahoma) Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Oct 2016 |
| 194 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 195 | Eott Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 1995 |
| 196 | EP Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 197 | Esco Exploration, Inc | Dallas, TX 75201 | Oil & Gas Operator | Mar 2015 |
| 198 | Esis Inc | | Oil & Gas Operator | Feb 2017 |
| 199 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 200 | Exok, Inc. | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2025 |