| 1 | G & H Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2009 |
| 2 | Gasco Inc | | Oil & Gas Operator | Jun 1998 |
| 3 | General Atlantic Resources Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 4 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 5 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 6 | GKM Inc | | Oil & Gas Operator | Mar 1990 |
| 7 | GLG Energy LP | Austin, TX 78701 | Oil & Gas Operator | Jun 1994 |
| 8 | GMT Energy Corporation | Houston, TX 77042 | Oil & Gas Operator | Feb 2005 |
| 9 | GMT Exploration Company LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 10 | Golden Energy Partners LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2010 |
| 11 | Goldmark Engineering Inc | Casper, WY 82602 | Oil & Gas Operator | Oct 2004 |
| 12 | Gpo Operations LLC | Labarge, WY 83123 | Oil & Gas Operator | Aug 2025 |
| 13 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 14 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 15 | Grayhorse Operating Inc | Tulsa, OK 74103-4439 | Oil & Gas Operator | Jun 2025 |
| 16 | Grayson Mill Operating LLC | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 17 | Great Northern Gas Company | Denver, CO 80293-0602 | Oil & Gas Operator | Jul 2017 |
| 18 | Great Western Drilling Co | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 19 | Greylock Production LLC | Charleston, WV 25311-1264 | Oil & Gas Operator | Jul 2025 |
| 20 | Grizzly Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2025 |
| 21 | Grynberg Petroleum Company | Greenwood Vge, CO 80111-3326 | Oil & Gas Operator | Oct 2019 |
| 22 | Grynberg, Jack J. | Denver, CO 80237 | Oil & Gas Operator | Jun 2021 |
| 23 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |