| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | U.S. Steel Mining Co., Inc. | Gas Operator | Jan 2000 | |
| 2 | U.S. Steel Mining Co., LLC | Gas Operator | Oct 2002 | |
| 3 | Union Exploration Partners, LTD. | Oil & Gas Operator | Aug 1990 | |
| 4 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 5 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 6 | Unit Manager, Citronelle Unit | Oil & Gas Operator | Sep 2001 |