| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 2 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 3 | Decalta International Corp | Denver, CO 80202 | Oil & Gas Operator | Mar 2015 |
| 4 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 5 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 6 | Diamond Oil & Gas LLC | Casper, WY 82604 | Oil & Gas Operator | Aug 2025 |
| 7 | Dolezal George Jr | Littleton, CO 80163 | Oil & Gas Operator | Sep 2006 |