| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | U. S. Energy Development Corporation | Fort Worth, TX 76164 | Oil & Gas Operator | Oct 2025 |
| 2 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 3 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | Oct 2025 |
| 4 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 5 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 6 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 7 | United Texas Petroleum Inc. | McKinney, TX 75070 | Oil & Gas Operator | Oct 2025 |