| 101 | Cool Spring Colony, Inc. | Rudyard, MT 59540 | Gas Operator | Nov 2025 |
| 102 | Coolidge, G. B., Inc. | Shelby, MT 59474 | Oil & Gas Operator | Aug 2016 |
| 103 | Coolidge, Paul | | Oil Operator | Sep 2025 |
| 104 | Coolidge, Timothy J & Billiette Nebel | Kevin, MT 59454 | Oil Operator | Sep 2025 |
| 105 | Cortez Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2016 |
| 106 | Costilla Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 107 | Cowry Enterprises, LTD. | Littleton, CO 80161-3310 | Oil & Gas Operator | Mar 2022 |
| 108 | Croft Petroleum Co. | Cut Bank, MT 59427 | Oil & Gas Operator | Dec 2022 |
| 109 | Crown Oil, Inc. | Houston, TX 77002 | Oil Operator | Jan 1999 |
| 110 | Crusader Energy Group Inc. | Austin, TX 78746 | Oil & Gas Operator | Mar 2015 |
| 111 | Cut Bank Gas Company | Cut Bank, MT 59427 | Gas Operator | May 2025 |
| 112 | CWT Operating, LLC | McKinney, TX 75072 | Oil & Gas Operator | Nov 2025 |
| 113 | D & H Energy, LLC | Shelby, MT 59474 | Oil & Gas Operator | Oct 2025 |
| 114 | D & M Welding LLC | Kevin, MT 59454 | Oil & Gas Operator | Dec 2025 |
| 115 | D.C. Oil | Natalia, TX 78059 | Oil Operator | Dec 2025 |
| 116 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 117 | Dankbar, LLC | Kevin, MT 59454 | Oil Operator | Nov 2025 |
| 118 | Darrah Oil Company, LLC | Wichita, KS 67201 | Oil & Gas Operator | Dec 2025 |
| 119 | Dart Oil & Gas Corporation | Mason, MI 48854 | Oil & Gas Operator | Jun 2018 |
| 120 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Dec 2025 |
| 121 | Delphi International, Inc. | Tulsa, OK 74104 | Oil Operator | Nov 2025 |
| 122 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 123 | Devon Energy Production Company, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 124 | Devon Energy Williston, L.L.C | Oklahoma City, OK 73102-8260 | Oil & Gas Operator | Nov 2025 |
| 125 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 126 | Diamond Halo Group LLC | Grandview, TX 76050 | Oil Operator | Oct 2025 |
| 127 | Diamond Oil & Gas LLC | Casper, WY 82604 | Oil & Gas Operator | Oct 2025 |
| 128 | Digital Operating Company LLC | Boerne, TX 78006 | Oil & Gas Operator | Dec 2025 |
| 129 | Diversified Operating Corp. | Golden, CO 80401 | Oil & Gas Operator | Oct 2012 |
| 130 | DL Energy, LLC | Saco, MT 59261 | Gas Operator | Nov 2025 |
| 131 | DNR Oil And Gas, Inc. | Englewood, CO 80155 | Oil & Gas Operator | Nov 2025 |
| 132 | Dominion Oklahoma Texas Exploration & Production | Houston, TX 77060 | Oil & Gas Operator | Dec 2006 |
| 133 | Drawings, LLC | Albuquerque, NM 87109 | Oil Operator | Aug 2025 |
| 134 | Dry Coulee Oil & Gas Company | Oilmont, MT 59466 | Oil Operator | Oct 2003 |
| 135 | Eagle Creek Colony | Galata, MT 59444 | Oil & Gas Operator | Oct 2025 |
| 136 | Eagle Oil & Gas Co. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2025 |
| 137 | Eagle Operating, Inc. | Minot, ND 58701 | Oil & Gas Operator | Nov 2025 |
| 138 | Earthstone Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2017 |
| 139 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2025 |
| 140 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 141 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Dec 2025 |
| 142 | Empire North Dakota LLC | Tulsa, OK 74114 | Oil & Gas Operator | Nov 2025 |
| 143 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 144 | Enclave Operating, LLC | Shelby, MT 59474 | Oil & Gas Operator | May 2014 |
| 145 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | Nov 2025 |
| 146 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 147 | Energy Corporation Of America | Charleston, WV 25311 | Oil & Gas Operator | Dec 2023 |
| 148 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Oct 2025 |
| 149 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Oct 2025 |
| 150 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Nov 2025 |
| 151 | Enneberg Oil & Gas | Kevin, MT 59454 | Oil Operator | Dec 2025 |
| 152 | EOG Resources Inc | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 153 | Equinor Energy LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2021 |
| 154 | Equitable Resources Energy Co, Western Region | Billings, MT 59102 | Oil & Gas Operator | May 1997 |
| 155 | Equity Oil Company | Salt Lake City, UT 84110-095 | Oil & Gas Operator | Aug 2004 |
| 156 | Fairways Exploration & Production, LLC | Houston, TX 77057 | Oil & Gas Operator | Dec 2025 |
| 157 | Faith Drilling, Inc. | | Gas Operator | Sep 1999 |
| 158 | FH Petroleum Corp. | Billings, MT 59103 | Oil & Gas Operator | Oct 2025 |
| 159 | Fidelity Exploration & Production Company | Denver, CO 80203 | Oil & Gas Operator | Nov 2025 |
| 160 | Five-Jab, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Dec 2025 |
| 161 | Florentine Exploration & Production, Inc. | | Oil Operator | Mar 1997 |
| 162 | Flying J Oil & Gas Inc | North Salt Lake, UT 84054 | Oil & Gas Operator | Dec 2009 |
| 163 | Forcenergy Inc | Miami, FL 33129 | Oil & Gas Operator | Mar 2015 |
| 164 | Forcenergy Onshore Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2012 |
| 165 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 166 | Forza Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2025 |
| 167 | Foster Energy Group, LLC | Wolfforth, TX 79382 | Oil & Gas Operator | Nov 2025 |
| 168 | Foundation Energy Management, LLC | Addison, TX 75001 | Oil & Gas Operator | Dec 2025 |
| 169 | Fulton Fuel Company | Shelby, MT 59474 | Oil & Gas Operator | Sep 2025 |
| 170 | Fulton Producing Co. | Shelby, MT 59474-0603 | Oil & Gas Operator | Feb 2005 |
| 171 | Fulton, William M. | Shelby, MT 59474 | Oil & Gas Operator | Feb 2005 |
| 172 | FX Drilling Company, Inc. | Cut Bank, MT 59427 | Oil & Gas Operator | Nov 2025 |
| 173 | G/S Producing, Inc. | Chester, MT 59522 | Oil & Gas Operator | Nov 2025 |
| 174 | Gallup City Oil, Inc. | Conrad, MT 59425 | Oil & Gas Operator | Mar 2011 |
| 175 | Gallup City Oil, LLC | Conrad, MT 59425 | Oil Operator | Oct 2025 |
| 176 | Garman Stripper Wells, LLC | Choteau, MT 59422 | Oil Operator | Nov 2025 |
| 177 | Genesis St Operating LLC | Kansas City, MO 64108 | Oil & Gas Operator | Dec 2025 |
| 178 | Georesources, Inc. | Williston, ND 58802-1505 | Oil & Gas Operator | Dec 2014 |
| 179 | Germany Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Oct 2002 |
| 180 | Glacier Minerals, LLC | The Woodlands, TX 77382 | Gas Operator | Nov 2025 |
| 181 | Glacier Production, Inc. | Cut Bank, MT 59427 | Oil Operator | Nov 2025 |
| 182 | Grand Resources, LTD. | Rockville, MD 20852 | Oil Operator | Jul 2025 |
| 183 | Granite Creek Energy LLC | Cody, WY 82414 | Oil & Gas Operator | Nov 2025 |
| 184 | Great Northern Drilling Company | Billings, MT 59103 | Oil & Gas Operator | Jun 2016 |
| 185 | Great Plains Energy, Inc. | Lincoln, NE 68516 | Oil & Gas Operator | Sep 2025 |
| 186 | Great Plains Operating, LLC. | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2014 |
| 187 | Great Plains Resources, Inc. | Nixon, TX 78140 | Oil & Gas Operator | Dec 2025 |
| 188 | Green Valley Operating, LLC | Billings, MT 59108 | Oil & Gas Operator | Nov 2025 |
| 189 | Grey Wolf Production Company, Inc. | Garnett, KS 66032-0426 | Oil Operator | Mar 2015 |
| 190 | Griffon & Associates, L.L.C. | Pearland, TX 77581 | Oil & Gas Operator | Jul 2008 |
| 191 | Griffon Petroleum, Inc. | Calgary, AB T2P 3K2 | Oil & Gas Operator | May 2007 |
| 192 | Grizzly Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2025 |
| 193 | Grynberg, Jack J. | Denver, CO 80237 | Oil & Gas Operator | Jun 2021 |
| 194 | Gypsy Highview Gathering System, Inc. | Cut Bank, MT 59427-0250 | Oil & Gas Operator | Oct 2000 |
| 195 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 196 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 197 | Hammond Valley Colony, Inc. | Harlowton, MT 59036 | Gas Operator | Nov 2025 |
| 198 | Hardrock Oil Company | Great Falls, MT 59403 | Gas Operator | Nov 2025 |
| 199 | Hawkins, Robert S. | Kevin, MT 59454 | Oil Operator | Jun 2018 |
| 200 | Hawley & Desimon | Conrad, MT 59425 | Oil Operator | Nov 2025 |