| 1 | Rains & Williams | | Oil & Gas Operator | Nov 1995 |
| 2 | Rains & Williamson Oil Co Inc | Wichita, KS 67277 | Oil & Gas Operator | Jun 2025 |
| 3 | Rama Operating Company Inc | Stafford, KS 67578 | Oil & Gas Operator | Aug 2025 |
| 4 | Raney Oil Company | Lawrence, KS 66047 | Oil & Gas Operator | May 1999 |
| 5 | Raney Oil Company, LLC | Lawrence, KS 66049 | Oil & Gas Operator | Jun 2025 |
| 6 | Raymond Oil Comp | | Oil & Gas Operator | Dec 1996 |
| 7 | Red Hills Energy, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Jun 2025 |
| 8 | Red Mountain Oil LLC | Golden, CO 80402 | Oil Operator | Nov 1997 |
| 9 | Red Oak Energy, Inc. | Wichita, KS 67207 | Oil & Gas Operator | Jun 2025 |
| 10 | Reef Operating, Inc. | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 11 | Reilly Oil Company, Inc. | Wakeeney, KS 67672 | Oil Operator | Jun 2025 |
| 12 | Reilly Oil E & P | | Oil Operator | Jun 2025 |
| 13 | Resource Operations Inc | Tulsa, OK 74157 | Oil & Gas Operator | May 2016 |
| 14 | Rice Engineering Corporation | Great Bend, KS 67530 | Oil & Gas Operator | Feb 2023 |
| 15 | Richlan Drilling | | Oil Operator | Dec 1994 |
| 16 | Richlan Drilling, A General Partnership | Beaver, KS 67525 | Oil & Gas Operator | Jun 2025 |
| 17 | Richland Oil Investments, LLC | Palco, KS 67657 | Oil Operator | Jun 2025 |
| 18 | Rider Oil & Gas | | Oil Operator | Aug 1991 |
| 19 | Ritchie Explorat | | Oil & Gas Operator | Dec 1996 |
| 20 | Ritchie Exploration | | Oil Operator | Aug 1995 |
| 21 | Ritchie Exploration, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Jun 2025 |
| 22 | Ritchie, A. Scott | Wichita, KS 67202 | Oil Operator | Mar 1988 |
| 23 | RL Investment, LLC | Hill City, KS 67642 | Oil Operator | Jun 2025 |
| 24 | RLT Investment | Morland, KS 67650 | Oil Operator | Mar 2009 |
| 25 | Rome Oil, LLC | Lakewood, CO 80232 | Oil Operator | Jun 2025 |
| 26 | Ron'S Oil Oper I | | Oil Operator | Nov 1994 |
| 27 | Ron'S Oil Operations Inc | Penokee, KS 67659 | Oil Operator | Dec 2018 |
| 28 | Royal Drilling Inc | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 29 | Running Foxes Petroleum Inc. | Centennial, CO 80112 | Oil & Gas Operator | Jun 2025 |
| 30 | Rush, Terry L. | Wakeeney, KS 67672 | Oil Operator | Jun 2025 |
| 31 | Russell Oil, Inc. | Edmond, OK 73083 | Oil Operator | Jun 2025 |