| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 2 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 3 | Hallwood Petroleum, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jan 2010 |
| 4 | Hanvey, Don H. Oil Interests Inc | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |