| 1 | C & C Oil Co. | Borger, TX 79008 | Oil & Gas Operator | Jul 2025 |
| 2 | C & S Oil Company | Odessa, TX 79763 | Oil & Gas Operator | Nov 2019 |
| 3 | C Rose Oil Co. | Midland, TX 79708 | Oil & Gas Operator | Jun 2025 |
| 4 | Cannuck Resources Inc | Nowata, OK 74048 | Oil & Gas Operator | Aug 2000 |
| 5 | Carman Frances J | Pawhuska, OK 74056-0101 | Oil & Gas Operator | Aug 2013 |
| 6 | Carter Donald L | Sand Springs, OK 74063-8105 | Oil Operator | May 2006 |
| 7 | Centrex Operating Company | Tulsa, OK 74105 | Oil & Gas Operator | Jul 2025 |
| 8 | Century Petroleum | Nowata, OK 74048 | Oil & Gas Operator | Dec 2000 |
| 9 | Cep Mid-Continent LLC | Skiatook, OK 74070 | Oil & Gas Operator | Jul 2025 |
| 10 | Chambers & Hendrix Oil & Gas | Skiatook, OK 74070-0726 | Oil & Gas Operator | Aug 2022 |
| 11 | Chatham John | Wilson, OK 73463-9575 | Oil Operator | Feb 2014 |
| 12 | Cimarron Production Co Inc | Oklahoma City, OK 73142-3017 | Oil & Gas Operator | Jul 2025 |
| 13 | Coe Production Company | Talala, OK 74080-0264 | Oil & Gas Operator | Aug 2015 |
| 14 | Coe Production Company LLC | Talala, OK 74080 | Oil Operator | Jul 2025 |
| 15 | Colpitt Brothers Oil | Collinsville, OK 74021 | Oil & Gas Operator | Apr 2020 |
| 16 | Colpitt C H Drilling Co LLC | Collinsville, OK 74021-7107 | Oil Operator | Jul 2025 |
| 17 | Colpitt Chas H Drilling Co | Collinsville, OK 74021-7105 | Oil & Gas Operator | Mar 2012 |
| 18 | Corbell Wayne L | Fort Worth, TX 76111-4615 | Oil & Gas Operator | Apr 2023 |
| 19 | County Line Stripper Wells LLC | Chelsea, OK 74016 | Oil & Gas Operator | May 2025 |
| 20 | Cox P D Inc | Bristow, OK 74010 | Oil & Gas Operator | May 1993 |
| 21 | Cricket Enterprises Corporation | Nowata, OK 74048-9683 | Oil & Gas Operator | Mar 2015 |