| 1 | Campanella, George L | Great Falls, MT 59403 | Oil & Gas Operator | Sep 2025 |
| 2 | Camwest II LP | McKinney, TX 75070 | Oil & Gas Operator | Jul 2007 |
| 3 | Camwest Limited Partnership | Denver, CO 80202 | Oil & Gas Operator | Apr 2004 |
| 4 | Capitan Operating LLC | Reno, NV 89502 | Oil & Gas Operator | Jan 2013 |
| 5 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 6 | Carrell Oil Company Dba Coco | Laurel, MT 59044 | Oil Operator | Jul 2020 |
| 7 | Castle Resources, Inc. | Russell, KS 67665 | Oil & Gas Operator | Jun 2025 |
| 8 | Cat Creek Holdings LLC | Winnett, MT 59087 | Oil Operator | Sep 2025 |
| 9 | Cavalier Petroleum | Shelby, MT 59474 | Oil & Gas Operator | Oct 2014 |
| 10 | Central Montana Resources, LLC | San Antonio, TX 78209 | Oil Operator | Jul 2015 |
| 11 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 12 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Sep 2025 |
| 13 | Chandler Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2009 |
| 14 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Nov 2025 |
| 15 | Charger Resources, LLC | Hurst, TX 76054 | Oil & Gas Operator | Aug 2015 |
| 16 | Charoil Co., J. Norm And Charlotte Sibley Dba | Roundup, MT 59072 | Oil Operator | Oct 2002 |
| 17 | Chelin LLC | Cut Bank, MT 59427 | Oil & Gas Operator | Aug 2025 |
| 18 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Nov 2025 |
| 19 | Chippewa Cree Tribe | | Gas Operator | Sep 2025 |
| 20 | Choctaw II Oil & Gas, LTD. | Houston, TX 77002 | Oil & Gas Operator | Jan 2002 |
| 21 | Cirque Resources LP | Denver, CO 80202 | Oil & Gas Operator | Aug 2016 |
| 22 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Nov 2025 |
| 23 | City Of Baker | Baker, MT 59313 | Oil & Gas Operator | Sep 2025 |
| 24 | Cline Production Company | Billings, MT 59104 | Oil & Gas Operator | Sep 2025 |
| 25 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2025 |
| 26 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 27 | Colossus Operating LLC | Kalispell, MT 59901 | Oil Operator | Sep 2025 |
| 28 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 29 | Columbia Petroleum, LTD. | Farmington, UT 84025 | Oil Operator | Sep 2025 |
| 30 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 31 | Columbus Energy, LLC | Houston, TX 77046 | Oil & Gas Operator | Nov 2025 |
| 32 | Comanche Drilling Company | Cut Bank, MT 59427 | Oil & Gas Operator | Jun 2025 |
| 33 | Compass Energy, Inc. | Shelby, MT 59474 | Gas Operator | Feb 2007 |
| 34 | Constitution Gas Transport Co., Inc. | Salt Lake City, UT 84124-1110 | Gas Operator | Jun 2012 |
| 35 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 36 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Nov 2025 |
| 37 | Coolidge, G. B., Inc. | Shelby, MT 59474 | Oil & Gas Operator | Aug 2016 |
| 38 | Coolidge, Paul | | Oil Operator | Sep 2025 |
| 39 | Coolidge, Tim & Billiette | Sunburst, MT 59482 | Oil Operator | Sep 2025 |
| 40 | Coolidge, Timothy J & Billiette Nebel | Kevin, MT 59454 | Oil Operator | Sep 2025 |
| 41 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 42 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 43 | Cowry Enterprises, LTD. | Littleton, CO 80161-3310 | Oil & Gas Operator | Mar 2022 |
| 44 | Croft Petroleum Co. | Cut Bank, MT 59427 | Oil & Gas Operator | Dec 2022 |
| 45 | Crown Oil, Inc. | Houston, TX 77002 | Oil Operator | Jan 1999 |
| 46 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 47 | Cut Bank Gas Company | Cut Bank, MT 59427 | Gas Operator | May 2025 |
| 48 | CWT Operating, LLC | McKinney, TX 75072 | Oil & Gas Operator | Sep 2025 |