| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | R & M Oil Co. | Fredonia, KS 66736 | Oil & Gas Operator | Aug 2002 |
| 2 | Radzewicz Operating Corp. | Oil & Gas Operator | Oct 2017 | |
| 3 | Riceland Petroleum Company | Oil & Gas Operator | Dec 2023 | |
| 4 | Rig Iron Petroleum Inc | Oil & Gas Operator | Aug 1988 | |
| 5 | Rio Bravo Expl. & Prod. Co. | Houston, TX 77055 | Oil & Gas Operator | Apr 2020 |
| 6 | Rio Bravo Oil Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2002 |
| 7 | River Bend Operating, Inc. | Oil & Gas Operator | Jul 1999 | |
| 8 | Roblyn Petroleum Corp. | Oil & Gas Operator | May 1983 | |
| 9 | Rozel Operating Company | Oil & Gas Operator | Oct 2014 | |
| 10 | Rvo Petroleum Co. | Oil & Gas Operator | Feb 1982 |