| 1 | S.E.D.I. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2015 |
| 2 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2024 |
| 3 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Dec 2024 |
| 4 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 5 | Schlachter, David A., Estate Of | Dallas, TX 75225 | Oil & Gas Operator | Jan 2000 |
| 6 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Dec 2024 |
| 7 | SFM Holdings, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jul 1995 |
| 8 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Dec 2022 |
| 9 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 10 | Southeastern Resources Corp. | Mansfield, TX 76063 | Oil & Gas Operator | Feb 2004 |
| 11 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Dec 2024 |
| 12 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 13 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 14 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |