| 1 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 2 | Saba Energy Of Texas Inc | Houston, TX 77042 | Oil & Gas Operator | Jul 2007 |
| 3 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 4 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 5 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Oct 2025 |
| 6 | Sage Butte PRB Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 7 | Sage Petroleum LLC | Casper, WY 82601 | Oil Operator | Jun 2008 |
| 8 | Salt Creek Operating LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2020 |
| 9 | Salt Creek West Partners | | Oil Operator | Jul 1995 |
| 10 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 11 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Aug 2025 |
| 12 | Samson Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 13 | Samson Resources Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |
| 14 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Jun 2025 |
| 15 | Sanchez-O'Brien | | Oil & Gas Operator | Dec 1984 |
| 16 | Sands Oil Company Inc | Billings, MT 59103 | Oil & Gas Operator | Jul 2025 |
| 17 | Sands-American Corp | | Oil & Gas Operator | Jan 1990 |
| 18 | Santa Rosa Petroleum LLC | Recluse, WY 82725 | Oil & Gas Operator | Aug 2025 |
| 19 | Sauer Bill Oil & Gas Company LLC | Casper, WY 82604 | Oil & Gas Operator | Jun 1999 |
| 20 | Saxon Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Oct 2009 |
| 21 | Sayers Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2005 |
| 22 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 23 | Scarlett Energy Enterprises LLC | Watchung, NJ 07069 | Oil & Gas Operator | Oct 2014 |
| 24 | Sceptre Resources Inc | | Oil & Gas Operator | Dec 2007 |
| 25 | Schiff & Jackson Oil Producers | Dallas, TX 75206 | Oil & Gas Operator | Jun 2025 |
| 26 | Schlaikjer A L | | Oil Operator | Feb 1997 |
| 27 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Oct 2025 |
| 28 | Schneider Oil Corporation | Broomfield, CO 80020 | Oil & Gas Operator | Aug 2009 |
| 29 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 30 | Seahawk Oil International Inc | Newport Beach, CA 92660 | Oil & Gas Operator | Oct 1997 |
| 31 | Seedy Draw LLC | Greenwood VIllage, CO 80111 | Oil Operator | Jul 2025 |
| 32 | Seer Operating LLC | Sheridan, WY 82801 | Oil & Gas Operator | Oct 2016 |
| 33 | Seguro Oil & Gas Inc | | Oil Operator | Jul 1992 |
| 34 | Sendero Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 35 | Seven Sisters Oil & Gas LLC | Casper, WY 82602 | Oil & Gas Operator | Jan 2022 |
| 36 | Shar Alan Oil Company | | Oil & Gas Operator | Oct 2005 |
| 37 | Sharkey Well Service Inc | | Oil Operator | Dec 2023 |
| 38 | Sharples Phillip T Trust | Denver, CO 80264 | Oil & Gas Operator | Nov 2020 |
| 39 | Shelco | Maysville, MO 64469 | Oil & Gas Operator | May 2021 |
| 40 | Shell Rocky Mountain Production LLC | Pinedale, WY 82941 | Oil & Gas Operator | Dec 2008 |
| 41 | Shenandoah Energy Inc | Denver, CO 80265-1050 | Oil & Gas Operator | Dec 2014 |
| 42 | Shenandoah Oil Corporation | | Oil & Gas Operator | Jun 1979 |
| 43 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2025 |
| 44 | Siegfried R H Inc | Tulsa, OK 74104 | Oil & Gas Operator | Mar 2008 |
| 45 | Sierra Trading Corporation | | Oil & Gas Operator | Sep 1978 |
| 46 | Signal Hill Company LLC | Cody, WY 82414 | Oil & Gas Operator | Dec 2024 |
| 47 | Signal Hill Operating LLC | | Oil & Gas Operator | Aug 2025 |
| 48 | Silverado Oil Inc | Greeley, CO 80631 | Oil Operator | Apr 2000 |
| 49 | Simasko Production Co | Denver, CO 80204 | Oil & Gas Operator | Nov 1997 |
| 50 | Simon Oil LLC | Kaycee, WY 82639 | Oil Operator | Jul 2025 |
| 51 | Simray Production Company LP | Richland, TX 75080 | Oil & Gas Operator | Dec 2010 |
| 52 | Six Bar Oil LLC | Pine Haven, WY 82721 | Oil & Gas Operator | Jul 2025 |
| 53 | Skidgel Enterprises Inc | Rawlins, WY 82301 | Oil & Gas Operator | Sep 2018 |
| 54 | Skinner Corporation | | Oil Operator | Apr 1985 |
| 55 | Skinner Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Jan 2024 |
| 56 | Skinner'S Resources & Expl Inc | | Oil & Gas Operator | Jun 2007 |
| 57 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 58 | Skull Creek A LLC | Douglas, WY 82633 | Oil & Gas Operator | Jul 2025 |
| 59 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 60 | Slaughter J M Oil Company | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2001 |
| 61 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 62 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 63 | Smith Al | Duncan, OK 73534-0037 | Oil Operator | Dec 1998 |
| 64 | Smith Conley P Operating Co | Eglewood, CO 80112-3640 | Oil & Gas Operator | Jun 2000 |
| 65 | Smith Kevin | Thermopolis, WY 82443 | Oil Operator | Sep 2024 |
| 66 | Smith Red Plains Production LLC | | Oil & Gas Operator | Aug 2025 |
| 67 | Smokey Gap Oil Company LLC | | Oil Operator | Aug 2025 |
| 68 | Smokey Oil Company Inc | Casper, WY 82601 | Oil & Gas Operator | Dec 1996 |
| 69 | Snowy Owl LLC | Gillette, WY 82717 | Oil & Gas Operator | Aug 2025 |
| 70 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 71 | Sois-Osage Inc | | Oil & Gas Operator | Oct 2006 |
| 72 | Solar Petroleum Inc | | Oil Operator | May 1983 |
| 73 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 74 | Sonoma Energy Corporation | Park City, UT 84068 | Oil & Gas Operator | Feb 2010 |
| 75 | Sonterra Energy LLC | Wichita, KS 67226 | Oil & Gas Operator | Jul 2022 |
| 76 | Sooner Operating Co Inc | Casper, WY 83602 | Oil Operator | Aug 2025 |
| 77 | Sourcegas Energy Services Co | Golden, CO 80401 | Gas Operator | Jun 2015 |
| 78 | South Coast Oil Corporation | Boulder, CO 80302 | Oil & Gas Operator | Oct 2015 |
| 79 | South Pass Petroleum Inc | Casper, WY 82601 | Oil & Gas Operator | Aug 2025 |
| 80 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 81 | Southern States Petroleum Corp | | Oil Operator | Jan 1984 |
| 82 | Southern Union Exploration | | Oil Operator | Jan 1990 |
| 83 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 84 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 85 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 86 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 87 | Southwestern Production Corporation | Lakewood, CO 80228 | Oil & Gas Operator | Aug 2025 |
| 88 | Spellbound Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 89 | Spirit Energy Inc | Edmond, OK 73034 | Oil & Gas Operator | Apr 1999 |
| 90 | Spring Valley Development Co LLC | Centennial, CO 80014 | Oil & Gas Operator | Jul 2025 |
| 91 | St Michael Exploration | | Oil & Gas Operator | Jun 1987 |
| 92 | St Oil Company | Denver, CO 80264-2101 | Oil & Gas Operator | Dec 2010 |
| 93 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 94 | Stag Oil Producers Inc | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 95 | Stanco Petroleum Inc | Kimball, NE 69145 | Oil & Gas Operator | Jul 1999 |
| 96 | Star Oil Operating Company LLC | Laramie, WY 82073 | Oil & Gas Operator | Aug 2025 |
| 97 | Star Resources LLC | Englewood, CO 80155-5185 | Oil & Gas Operator | Dec 2013 |
| 98 | States Exploration Inc | | Oil Operator | Jul 1985 |
| 99 | Statex Petroleum Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 100 | Stealth Energy Inc | Billings, MT 59101 | Oil Operator | Dec 2011 |