| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Gary-Williams Production Company | Denver, CO 80202 | Oil & Gas Operator | May 2000 |
| 2 | Gasco Inc | Oil & Gas Operator | Jun 1998 | |
| 3 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 4 | GKM Inc | Oil & Gas Operator | Mar 1990 | |
| 5 | GMT Exploration Company LLC | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 6 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 7 | GRB Resources | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2004 |
| 8 | Greenstreet Lloyd | Oil Operator | Dec 1986 | |
| 9 | Grizzly Operating LLC | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 10 | GRMR Oil And Gas LLC | Broomfield, CO 80021 | Oil & Gas Operator | Jun 2025 |
| 11 | Gulf Energy Corporation | Denver, CO 80237 | Oil & Gas Operator | Jun 1987 |
| 12 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |