| 1 | S O Utah | Irvine, CA 92715 | Oil & Gas Operator | Sep 1994 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 4 | Santa Fe Snyder Corporation | Houston, TX 77024 | Oil & Gas Operator | Oct 2000 |
| 5 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 6 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 7 | Sep Nosr LLC | Orem, UT 84097 | Oil & Gas Operator | Feb 2025 |
| 8 | Sfeop | Midland, TX 79701 | Oil & Gas Operator | Mar 1994 |
| 9 | Shell Oil Co. | Houston, TX 77001 | Oil & Gas Operator | Jun 1985 |
| 10 | Shenandoah Energy Inc | Denver, CO 80265-1050 | Oil & Gas Operator | Dec 2014 |
| 11 | Shiny One Operating Company, LLC | Vernal, UT 84078 | Oil & Gas Operator | Jan 2025 |
| 12 | Sinclair Oil & Gas Company | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Apr 2025 |
| 13 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 14 | Slate River Resources LLC | Denver, CO 80293 | Oil & Gas Operator | Apr 2008 |
| 15 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Apr 2025 |
| 16 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 17 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 18 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 19 | Standard Oil Co Of Calif | | Oil & Gas Operator | Dec 1983 |
| 20 | Stewart Petroleum Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Dec 2023 |
| 21 | Stone, D J | Palo Alto, CA 94301 | Oil & Gas Operator | Sep 1985 |
| 22 | Summit Operating LLC | Boulder, CO 80301 | Oil & Gas Operator | Feb 2025 |
| 23 | Sun Explor & Production Co | Oklahoma City, OK 73126 | Gas Operator | Oct 1984 |
| 24 | Sun Oil Company | Arlington, TX 76006 | Oil & Gas Operator | Dec 2021 |
| 25 | Sunray DX Oil Co | | Gas Operator | Dec 1983 |
| 26 | Swepi/Western Division | Houston, TX 77210 | Oil & Gas Operator | Aug 1984 |
| 27 | Swevco-Sabw LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |