| 1 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Mar 2026 |
| 2 | Rathbun Roger | | Oil & Gas Operator | Dec 1993 |
| 3 | Rathpro Inc | Douglas, WY 82633 | Oil & Gas Operator | Feb 1994 |
| 4 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 5 | Reading & Bates Petroleum | | Oil & Gas Operator | Apr 1989 |
| 6 | Red Rock Resources Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Feb 2026 |
| 7 | Remuda Energy Development LLC | Billings, MT 59104 | Oil & Gas Operator | Feb 2026 |
| 8 | Renos Land & Minerals Company | Casper, WY 82601 | Oil & Gas Operator | Oct 2021 |
| 9 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 10 | Reunion Energy Company | Houston, TX 77056 | Oil & Gas Operator | May 1996 |
| 11 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Feb 2026 |
| 12 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | May 2026 |
| 13 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | May 2026 |
| 14 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 15 | Robert Hawkins Inc | Kevin, MT 59454 | Oil & Gas Operator | Feb 2026 |
| 16 | Rochelle Oil & Gas | Gillette, WY 82717 | Oil & Gas Operator | Mar 2024 |
| 17 | Rockies Resources Holdings LLC | Lakewood, CO 80228 | Oil & Gas Operator | Feb 2026 |
| 18 | Rocky Mountain Gas Inc | Sheridan, WY 82801 | Gas Operator | Nov 2009 |
| 19 | Rosa Petroleum | Evansville, WY 82636 | Oil Operator | Dec 1995 |