| 1 | Aberdeen Petroleum (USA) Inc. | Abilene, TX 79608 | Oil & Gas Operator | Sep 1994 |
| 2 | Aethon Energy Operating LLC | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 3 | Alpha Petrovision Us Inc | Canada, 00100 | Oil & Gas Operator | May 2013 |
| 4 | Amerada Hess Corporation | Houston, TX 77252 | Oil & Gas Operator | Aug 2013 |
| 5 | Anadarko E&P Onshore LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 6 | Angus Petroleum Corporation | Chicago, IL 60660 | Oil & Gas Operator | Dec 2022 |
| 7 | Anschutz Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 8 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 9 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 10 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 11 | Arapaho Petroleum Inc | Englewood, CO 80155 | Oil & Gas Operator | Nov 1998 |
| 12 | Arnell Oil Company | Centennial, CO 80122 | Oil & Gas Operator | Jul 2025 |
| 13 | Ashland Exploration | | Oil & Gas Operator | May 1979 |
| 14 | Atlantic Oil Corporation | Denver, CO 80206 | Oil & Gas Operator | Dec 1982 |
| 15 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |
| 16 | Bass Enterprises Production Co | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2006 |
| 17 | Bates Creek Oil | | Oil Operator | Dec 1986 |
| 18 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Aug 2025 |
| 19 | Berco Resources LLC | Denver, CO 80206 | Oil & Gas Operator | Sep 2009 |
| 20 | Beren Corporation | Wichita, KS 67206 | Oil & Gas Operator | Oct 2025 |
| 21 | BHP Petroleum (USA) Inc | | Oil & Gas Operator | Mar 1993 |
| 22 | BHP Petroleum Company Inc | Houston, TX 77057 | Oil & Gas Operator | Jun 2016 |
| 23 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 24 | Black Bear Oil Corporation | Las Vegas, NV 89128 | Oil & Gas Operator | Aug 2025 |
| 25 | Black Gold Services Inc | Casper, WY 82644 | Oil & Gas Operator | Aug 2025 |
| 26 | Blue Tip Energy Wyoming Inc | Houston, TX 77284 | Oil Operator | Jun 2016 |
| 27 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 28 | BP Exploration Inc | | Oil & Gas Operator | May 1993 |
| 29 | Breck Operating Corp. | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2025 |
| 30 | Breitburn Energy Company LLC | Lakewood, CO 80227 | Oil Operator | Aug 2011 |
| 31 | Breitburn Operating LP | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 32 | Brighton Energy LLC | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 33 | Brooks Exploration, Inc. | Denver, CO 80293 | Oil & Gas Operator | Mar 2001 |
| 34 | Brown Tom Inc | Dallas, TX 75240 | Oil & Gas Operator | Mar 2015 |
| 35 | Bummer Bruce L | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 36 | Burlington Resources Oil & Gas Company L | Gillette, WY 82718 | Oil & Gas Operator | Jan 2022 |
| 37 | Burr Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2019 |
| 38 | Butler Oil Co | Casper, WY 82602 | Oil & Gas Operator | Dec 1996 |
| 39 | Callaway Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Jul 2025 |
| 40 | Capitan Operating LLC | Reno, NV 89502 | Oil & Gas Operator | Jan 2013 |
| 41 | Carol-Holly Oil Corporation | Denver, CO 80237 | Oil & Gas Operator | Aug 2025 |
| 42 | Cenex | | Oil & Gas Operator | Dec 1996 |
| 43 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 44 | Century Oil & Gas Corporation | | Oil & Gas Operator | Dec 1987 |
| 45 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Aug 2025 |
| 46 | Chaparral Resources Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 1996 |
| 47 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 48 | Cheetah Oil Inc | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 49 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 50 | Christmann John J | Lubbock, TX 79401 | Oil & Gas Operator | Dec 1994 |
| 51 | CHS McPherson Refinery Inc | Platteville, CO 80651 | Oil & Gas Operator | Apr 1994 |
| 52 | Cig Exploration | Denver, CO 80201 | Oil & Gas Operator | Sep 1999 |
| 53 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Oct 2025 |
| 54 | Clark Oil Producing Company | | Oil & Gas Operator | Oct 1979 |
| 55 | Cloud Peak Operating LLC | Casper, WY 82601 | Oil Operator | Jul 2025 |
| 56 | Coaleum Corporation | Dallas, TX 75205 | Oil & Gas Operator | Jan 2001 |
| 57 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 58 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 59 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 60 | Contango Resources LLC | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 61 | Contango Rocky Mountain Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2020 |
| 62 | Continental Industries LC | Casper, WY 82602 | Oil & Gas Operator | Feb 2008 |
| 63 | Continental Production Co LLC | Greenwood VIllage, CO 80155 | Oil & Gas Operator | Aug 2012 |
| 64 | CR Energy | | Oil & Gas Operator | Dec 1992 |
| 65 | Creek Oil Company | Colorado Springs, CO 80906 | Oil & Gas Operator | Aug 2001 |
| 66 | Crowheart Energy LLC | Baggs, WY 82321 | Oil & Gas Operator | Jul 2025 |
| 67 | Dahill Murray P | Casper, WY 82601 | Oil & Gas Operator | Jun 2007 |
| 68 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 69 | Davis Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 1988 |
| 70 | Debord Oil Producers | Lincoln, NE 68503 | Oil Operator | Dec 1998 |
| 71 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 72 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 73 | Department Of Energy | Casper, WY 82601 | Oil & Gas Operator | Jan 2015 |
| 74 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 75 | Dietrich Resources Corporation | | Oil & Gas Operator | Jun 2007 |
| 76 | Dome Petroleum Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2016 |
| 77 | Dyco Petroleum Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2015 |
| 78 | E & B Natural Resources Management | Guilderland Centek, NY 12085 | Oil & Gas Operator | Aug 2025 |
| 79 | Eex Corporation | Houston, TX 77060 | Oil & Gas Operator | Feb 2000 |
| 80 | Elf Aquitaine Inc | Houston, TX 77002 | Oil & Gas Operator | May 1991 |
| 81 | Elk Petroleum Inc | Casper, WY 82601 | Oil & Gas Operator | Aug 2014 |
| 82 | Elm Ridge Exploration Company LLC | Bloomfield, NM 87413 | Oil & Gas Operator | Nov 2017 |
| 83 | Emerald Operating Company | Plano, TX 75075 | Oil & Gas Operator | Aug 2025 |
| 84 | Enerex Limited Liability Co | Craig, CO 81625 | Oil & Gas Operator | Jul 2025 |
| 85 | Energy Search Company Inc | Aurora, CO 80011 | Oil & Gas Operator | Jun 2021 |
| 86 | Envirosearch Corporation | | Oil Operator | Dec 1992 |
| 87 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 88 | EOG Y Resources Inc | Artesia, NM 88210 | Oil & Gas Operator | Feb 2019 |
| 89 | Equitable Resources Energy Company | Big Stone Gap, VA 24219 | Oil & Gas Operator | Dec 1997 |
| 90 | Escalera Resources Co | Casper, WY 82602 | Oil & Gas Operator | May 2018 |
| 91 | Everest Oil & Gas LLC | Santa Barbara, CA 93101 | Oil Operator | Jul 2025 |
| 92 | Evertson Operating Company Inc | Kimball, NE 69145 | Oil & Gas Operator | Nov 2022 |
| 93 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Jun 2025 |
| 94 | Exeter Drilling Company | Denver, CO 80217 | Oil & Gas Operator | Sep 1997 |
| 95 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 96 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Jul 2025 |
| 97 | Fancher Oil LLC | Greenwood, CO 80111 | Oil & Gas Operator | Nov 2006 |
| 98 | FDL Operating, LLC | Judson, TX 75660 | Oil & Gas Operator | Oct 2025 |
| 99 | Ferguson & Bosworth | | Oil & Gas Operator | May 2007 |
| 100 | Ferguson Oil Company Inc | | Oil & Gas Operator | Apr 1994 |