| 1 | A & G Oil & Gas | Shelby, MT 59474 | Oil & Gas Operator | Jul 2011 |
| 2 | A. B. Energy LLC | Chester, MT 59522 | Oil & Gas Operator | Mar 2021 |
| 3 | Abraxas Petroleum Corporation | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2021 |
| 4 | Aikins Drilling Company | Mohave Valley, AZ 86440 | Oil Operator | Dec 2019 |
| 5 | Ajax Oil Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2003 |
| 6 | Alme, Henry A. | Cut Bank, MT 59427 | Gas Operator | Dec 2020 |
| 7 | Alta VIsta Oil Corporation | Clearmont, WY 82835 | Oil & Gas Operator | Mar 2021 |
| 8 | Altamont Oil & Gas Inc. | Cut Bank, MT 59427-0200 | Oil & Gas Operator | May 2012 |
| 9 | Alturas Energy, LLC | Sidney, MT 59270 | Oil Operator | Sep 2015 |
| 10 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 11 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 12 | Anadarko Minerals, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2021 |
| 13 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Sep 2017 |
| 14 | Ansbro Petroleum Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2008 |
| 15 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Jun 2021 |
| 16 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 17 | Apex Energy, L.L.C. | Tulsa, OK 74114 | Oil & Gas Operator | Mar 2021 |
| 18 | Armstrong Operating, Inc. | Dickinson, ND 58602 | Oil & Gas Operator | Apr 2021 |
| 19 | Artex Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Dec 2020 |
| 20 | Assiniboine & Sioux Tribes | | Oil & Gas Operator | Mar 1997 |
| 21 | Athena Energy LLC | Toronto, ON M5E 1W7 | Gas Operator | Jan 2011 |
| 22 | Austin, Chas W | | Oil Operator | Jan 2009 |
| 23 | Aztec Gas And Oil Corporation | Elephant Butte, NM 87935-0370 | Oil & Gas Operator | Mar 2005 |
| 24 | Baldwin Lynch Energy Corp. | Fort Collins, CO 80525-3354 | Oil Operator | Feb 2021 |
| 25 | Balko, Inc. | Conrad, MT 59425 | Oil & Gas Operator | Jan 2021 |
| 26 | Ballantyne Ventures LLC | Shelby, MT 59474 | Oil & Gas Operator | Dec 2020 |
| 27 | Ballard Petroleum Holdings LLC | Billings, MT 59104 | Oil & Gas Operator | Apr 2021 |
| 28 | Basic Earth Science Systems, Inc. | Austin, TX 78714 | Oil & Gas Operator | Apr 2010 |
| 29 | Bayswater Exploration & Production LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2021 |
| 30 | BBX Operating Co. LLC | Austin, TX 78738 | Oil & Gas Operator | Nov 2020 |
| 31 | Beartooth Oil & Gas Company | Billings, MT 59103 | Oil & Gas Operator | Apr 2021 |
| 32 | Behm Energy, Inc. | Minot, ND 58702 | Oil & Gas Operator | Apr 2021 |
| 33 | Bensun Energy, LLC | Grandview, TX 76050 | Oil Operator | Aug 2020 |
| 34 | Berco Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Feb 2002 |
| 35 | Beren Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jun 2021 |
| 36 | Berenergy Corporation | Denver, CO 80217 | Oil & Gas Operator | Apr 2021 |
| 37 | Berexco LLC | Wichita, KS 67206 | Oil & Gas Operator | Jun 2021 |
| 38 | Big Gully Oil, LLC | Roundup, MT 59072 | Oil Operator | Apr 2021 |
| 39 | Big Sky Energy, LLC | Cody, WY 82413 | Oil & Gas Operator | Jan 2021 |
| 40 | Big Snowy Resources LP | Billings, MT 59105 | Oil Operator | Mar 2021 |
| 41 | Bill Barrett Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 42 | Black Hawk Resources, LLC | Bowman, ND 58623 | Oil & Gas Operator | Jun 2011 |
| 43 | Blackjack Oil, Inc. | Las Vegas, NV 89128 | Oil & Gas Operator | Nov 2019 |
| 44 | Blackstone Operating | Red Lodge, MT 59068 | Gas Operator | Dec 2006 |
| 45 | Bluebonnet Energy Corporation | Englewood, CO 80112 | Oil & Gas Operator | Apr 2021 |
| 46 | Bowers Oil & Gas, Inc. | Grand Junction, CO 81505-1097 | Oil & Gas Operator | Apr 2021 |
| 47 | Brainstorm Energy, Inc. | Whitefish, MT 59937 | Oil & Gas Operator | Dec 2020 |
| 48 | Branch Oil & Gas | Shelby, MT 59474-0766 | Oil & Gas Operator | Jul 2010 |
| 49 | Branch, Jerry L. | | Oil & Gas Operator | Jul 1999 |
| 50 | Brandon Oil Company | Sunburst, MT 59482 | Oil & Gas Operator | Mar 2021 |
| 51 | Breck Operating Corp. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2021 |
| 52 | Brighton Energy, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2009 |
| 53 | Briscoe Petroleum LLC | Sheridan, WY 82801 | Oil Operator | Apr 2021 |
| 54 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2000 |
| 55 | Brooks Exploration, Inc. | Denver, CO 80293 | Oil & Gas Operator | Apr 1997 |
| 56 | Brown, J. Burns Operating Co. | Havre, MT 59501 | Oil & Gas Operator | Mar 2021 |
| 57 | Bta Oil Producers, LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2021 |
| 58 | Buckley, Michael T. | Sweetgrass, MT 59484 | Oil Operator | Jan 2021 |
| 59 | Burlington Resources Oil & Gas Company LP | Houston, TX 77252 | Oil & Gas Operator | Jun 2021 |
| 60 | Bye, April & Scott | Kevin, MT 59454 | Oil & Gas Operator | Feb 2021 |
| 61 | Campanella, George L | Great Falls, MT 59403 | Oil & Gas Operator | Mar 2021 |
| 62 | Camwest II LP | McKinney, TX 75070 | Oil & Gas Operator | Jul 2007 |
| 63 | Camwest Limited Partnership | Denver, CO 80202 | Oil & Gas Operator | Apr 2004 |
| 64 | Capitan Operating LLC | Reno, NV 89502 | Oil & Gas Operator | Jan 2013 |
| 65 | Carbon Energy Corporation (USA) | Denver, CO 80290 | Oil & Gas Operator | Jul 2004 |
| 66 | Carrell Oil Company Dba Coco | Laurel, MT 59044 | Oil Operator | Jul 2020 |
| 67 | Castle Resources, Inc. | Russell, KS 67665 | Oil & Gas Operator | Dec 2019 |
| 68 | Cat Creek Holdings LLC | Winnett, MT 59087 | Oil Operator | Mar 2021 |
| 69 | Cavalier Petroleum | Shelby, MT 59474 | Oil & Gas Operator | Oct 2014 |
| 70 | Central Montana Resources, LLC | San Antonio, TX 78209 | Oil Operator | Jul 2015 |
| 71 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 72 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Apr 2021 |
| 73 | Chandler Energy, LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2009 |
| 74 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73114 | Oil & Gas Operator | Jun 2021 |
| 75 | Charger Resources, LLC | Hurst, TX 76054 | Oil & Gas Operator | Aug 2015 |
| 76 | Charoil Co., J. Norm And Charlotte Sibley Dba | Roundup, MT 59072 | Oil Operator | Oct 2002 |
| 77 | Chelin LLC | Cut Bank, MT 59427 | Oil & Gas Operator | Mar 2021 |
| 78 | Chesapeake Operating, LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jun 2021 |
| 79 | Chippewa Cree Tribe | | Gas Operator | Mar 2019 |
| 80 | Choctaw II Oil & Gas, LTD. | Houston, TX 77002 | Oil & Gas Operator | Jan 2002 |
| 81 | Cirque Resources LP | Denver, CO 80202 | Oil & Gas Operator | Aug 2016 |
| 82 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Jun 2021 |
| 83 | City Of Baker | Baker, MT 59313 | Gas Operator | Mar 2021 |
| 84 | Cline Production Company | Billings, MT 59104 | Oil & Gas Operator | Mar 2021 |
| 85 | Cody Energy, Inc. | Houston, TX 77077 | Oil & Gas Operator | Apr 2021 |
| 86 | Collins & Ware, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 87 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | May 2001 |
| 88 | Columbia Petroleum, LTD. | Farmington, UT 84025 | Oil Operator | Mar 2021 |
| 89 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 90 | Columbus Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2021 |
| 91 | Comanche Drilling Company | Cut Bank, MT 59427 | Oil & Gas Operator | Mar 2021 |
| 92 | Compass Energy, Inc. | Shelby, MT 59474 | Gas Operator | Feb 2007 |
| 93 | Constitution Gas Transport Co., Inc. | Salt Lake City, UT 84124-1110 | Gas Operator | Jun 2012 |
| 94 | Contango Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2021 |
| 95 | Continental Resources Inc | Oklahoma City, OK 73126 | Oil & Gas Operator | Apr 2021 |
| 96 | Coolidge, G. B., Inc. | Shelby, MT 59474 | Oil & Gas Operator | Aug 2016 |
| 97 | Coolidge, Paul | | Oil Operator | Feb 2021 |
| 98 | Coolidge, Timothy J & Billiette Nebel | Kevin, MT 59454 | Oil Operator | Jan 2021 |
| 99 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2004 |
| 100 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |