| 1 | C & A Oil Company | Edmond, OK 73013-9413 | Oil & Gas Operator | Mar 2015 |
| 2 | C & B Energy Resources | Bartlesville, OK 74006 | Oil & Gas Operator | Mar 2015 |
| 3 | C & H Oil Company | Ratliff City, OK 73481-0130 | Oil & Gas Operator | Apr 2015 |
| 4 | C & J Trucks LLC | Seminole, OK 74868-5406 | Oil & Gas Operator | Jan 2026 |
| 5 | C E L Inc | Bartlesville, OK 74006 | Oil & Gas Operator | Jan 2020 |
| 6 | Call Harold Charles | Dewey, OK 74029 | Oil Operator | Nov 2025 |
| 7 | Call, Harold L | | Oil Operator | Mar 2015 |
| 8 | Cannuck Resources Inc | Nowata, OK 74048 | Oil & Gas Operator | Aug 2000 |
| 9 | Carl E Gungoll Exploration LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Dec 2025 |
| 10 | Carlton, Richard L | | Oil & Gas Operator | Aug 1999 |
| 11 | Cassidy Jr John | Stroud, OK 74079-0200 | Oil & Gas Operator | Nov 2014 |
| 12 | Castella Inc | Bartlesville, OK 74003-3712 | Oil & Gas Operator | Dec 2025 |
| 13 | CBM Gas Company LLC | Dewey, OK 74029 | Oil & Gas Operator | Aug 2020 |
| 14 | CCS Investments Inc | Bartlesville, OK 74006-1941 | Oil Operator | Nov 2025 |
| 15 | Century Petroleum | Nowata, OK 74048 | Oil & Gas Operator | Dec 2000 |
| 16 | Cep Mid-Continent LLC | Skiatook, OK 74070 | Oil & Gas Operator | Nov 2025 |
| 17 | Chew-Coast & Sons | Bartlesville, OK 74006-0407 | Gas Operator | Dec 2012 |
| 18 | Class Petroleum Corporation | Barnsdall, OK 74002 | Oil Operator | Aug 2013 |
| 19 | Clindco Inc | Bartlesville, OK 74006-6213 | Oil & Gas Operator | Oct 2019 |
| 20 | CLM Oil Production Inc | Bartlesville, OK 74006-4417 | Oil & Gas Operator | Nov 2025 |
| 21 | CMC Oil & Gas Inc | Bartlesville, OK 74006 | Oil & Gas Operator | Jun 1994 |
| 22 | CMR Operating LLC | Tulsa, OK 74135-2653 | Oil & Gas Operator | Jun 2018 |
| 23 | Cobalt Environmental Solutions LLC | Oklahoma City, OK 73101-0249 | Oil Operator | Jun 2019 |
| 24 | Coe Production Company | Talala, OK 74080-0264 | Oil & Gas Operator | Aug 2015 |
| 25 | Coe Production Company LLC | Talala, OK 74080 | Oil Operator | Nov 2025 |
| 26 | Coldren Oil & Gas Inc | Bartlesville, OK 74006-4729 | Oil & Gas Operator | Sep 1998 |
| 27 | Coleman Oil Company | Bartlesville, OK 74003 | Oil Operator | Dec 2024 |
| 28 | Collins Petroleum Inc | Bartlesville, OK 74006-7024 | Oil & Gas Operator | Apr 2005 |
| 29 | Collins, Stephen M | | Oil Operator | Nov 2025 |
| 30 | Colpitt C H Drilling Co LLC | Collinsville, OK 74021-7107 | Oil Operator | Nov 2025 |
| 31 | Colpitt Chas H Drilling Co | Collinsville, OK 74021-7105 | Oil & Gas Operator | Mar 2012 |
| 32 | Condrin Oil 1985-A LTD | Tulsa, OK 74136 | Oil & Gas Operator | Nov 1998 |
| 33 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Feb 2026 |
| 34 | Cook Anthony E | Coraopolis, PA 15108 | Oil & Gas Operator | Jan 2007 |
| 35 | Cook L D | Bartlesville, OK 74005-2306 | Oil & Gas Operator | Nov 2005 |
| 36 | Coon Creek Gas Inc | | Oil & Gas Operator | Mar 2014 |
| 37 | Corporate America Res Inc | Bartlesville, OK 74003 | Oil & Gas Operator | Jul 2005 |
| 38 | CVR Supply & Trading, LLC | Sugar Land, TX 77479 | Oil & Gas Operator | Apr 2024 |