| 101 | Breitburn Energy Company LLC | Lakewood, CO 80227 | Oil Operator | Aug 2011 |
| 102 | Breitburn Operating LP | Keithville, LA 71047 | Oil & Gas Operator | Sep 2026 |
| 103 | Brent Exploration | | Oil & Gas Operator | Dec 1993 |
| 104 | Bridger Petroleum Corp | | Oil & Gas Operator | Oct 1999 |
| 105 | Bridwell Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2026 |
| 106 | Brigham Oil & Gas, L.P. | Austin, TX 78730 | Oil & Gas Operator | Oct 2015 |
| 107 | Bright Rock Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Nov 2024 |
| 108 | Brighton Energy, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 109 | Briscoe Petroleum, LLC | Sheridan, WY 82801 | Oil & Gas Operator | Jul 2026 |
| 110 | Bristol Resources Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2022 |
| 111 | Bronco Oil & Gas Co | Casper, WY 82602 | Oil & Gas Operator | Oct 1987 |
| 112 | Brooks Exploration Inc | Denver, CO 80293 | Oil & Gas Operator | Mar 2001 |
| 113 | Brower Oil & Gas Inc | Jenks, OK 74037 | Oil & Gas Operator | Nov 2022 |
| 114 | Brown & Bickerstaff | | Oil & Gas Operator | Oct 1991 |
| 115 | Brown Doug & Larita | Newcastle, WY 82701 | Oil & Gas Operator | Jun 2025 |
| 116 | Brown J K Inc | Denver, CO 80202 | Oil & Gas Operator | Jan 2003 |
| 117 | Brown Operating Inc | Casper, WY 82602 | Oil & Gas Operator | May 2019 |
| 118 | Brown Shirley | Buffalo, WY 82834 | Oil & Gas Operator | Oct 2010 |
| 119 | Brown Tom Inc | Dallas, TX 75240 | Oil & Gas Operator | Mar 2015 |
| 120 | Bta Oil Producers, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 121 | Buchanan Wayman W | San Antonio, TX 78212 | Oil & Gas Operator | Sep 1990 |
| 122 | Buck Creek Freight Inc | Lusk, WY 82225 | Oil Operator | Jul 2026 |
| 123 | Buffalo Resources LLC | Woodward, OK 73801 | Oil & Gas Operator | Aug 2025 |
| 124 | Bullock A O | Casper, WY 82604 | Oil & Gas Operator | Apr 2026 |
| 125 | Bullock Gladys C Trust | | Oil & Gas Operator | Dec 1999 |
| 126 | Bummer Bruce L | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 127 | Bunkirt J J Oil & Gas Corporation | Powell, WY 82435 | Oil & Gas Operator | Jul 2026 |
| 128 | Burk Royalty Co., LTD. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2026 |
| 129 | Burlington Resources Oil & Gas Company L | Gillette, WY 82718 | Oil & Gas Operator | Jan 2022 |
| 130 | Burnett Oil Co Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2026 |
| 131 | Burr Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2019 |
| 132 | Butler Oil Co | Casper, WY 82602 | Oil & Gas Operator | Dec 1996 |
| 133 | BW Oil LLC | Hamel, MN 55340 | Oil Operator | Jun 2015 |
| 134 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 135 | BXP Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Sep 2026 |
| 136 | Byron Oil Industries Inc | Ballwin, MO 63011 | Oil & Gas Operator | Apr 2019 |
| 137 | C & H Well Servicing Inc | Gillette, WY 82717 | Oil & Gas Operator | Jul 2026 |
| 138 | C & K Petroleum | | Oil & Gas Operator | Jan 1984 |
| 139 | C And M Oil Inc | Kimball, NE 69145 | Oil & Gas Operator | Dec 2024 |
| 140 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 141 | Caerus Northern Rockies LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2021 |
| 142 | Calco Inc | | Oil & Gas Operator | Feb 1991 |
| 143 | Callaway Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Jun 2026 |
| 144 | Cambria Oil Company | Casper, WY 82601 | Oil & Gas Operator | Dec 1996 |
| 145 | Camwest II LP | McKinney, TX 75070 | Oil & Gas Operator | Jul 2007 |
| 146 | Camwest Limited Partnership | Denver, CO 80202 | Oil & Gas Operator | Apr 2004 |
| 147 | Canvasback Resources, LLC | | Oil & Gas Operator | Jul 2026 |
| 148 | Capitan Operating LLC | Reno, NV 89502 | Oil & Gas Operator | Jan 2013 |
| 149 | Capitol Oil & Gas Corporation | Centennial, WY 82055 | Oil Operator | Feb 2006 |
| 150 | Carbon Creek Energy LLC | Sheridan, WY 82801 | Oil & Gas Operator | Apr 2026 |
| 151 | Cardinal Wyoming LLC | | Oil & Gas Operator | Jul 2026 |
| 152 | Carlson Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 153 | Carol-Holly Oil Corporation | Denver, CO 80237 | Oil & Gas Operator | Jul 2026 |
| 154 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 155 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 156 | Castle Rock Oil LLC | | Oil Operator | Jul 2026 |
| 157 | Cat Oil | Byron, WY 82412 | Oil Operator | May 2001 |
| 158 | Caza Exploration Company | | Oil Operator | Nov 1991 |
| 159 | CCRP Operating Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2024 |
| 160 | CDX Gas, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2009 |
| 161 | Cedar Resources Corporation | Gillette, WY 82717 | Gas Operator | Dec 2010 |
| 162 | Cedar Ridge Operating Co LLC | Durango, CO 81303 | Gas Operator | Dec 2009 |
| 163 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 164 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 165 | Cenergy Resources LLC | | Oil & Gas Operator | Jul 2026 |
| 166 | Cenex | | Oil & Gas Operator | Dec 1996 |
| 167 | Centennial Energy | Thermopolis, WY 82443 | Oil & Gas Operator | May 2026 |
| 168 | Central Operating Inc | Denver, CO 80202 | Oil & Gas Operator | May 2026 |
| 169 | Central Resources, Inc. | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 170 | Central Wyoming Resources LTD | Glenrock, WY 82637 | Oil Operator | Jul 2021 |
| 171 | Century Energy | Gillette, WY 82717 | Oil & Gas Operator | Dec 1996 |
| 172 | Century Oil & Gas Corporation | | Oil & Gas Operator | Dec 1987 |
| 173 | Century Oil And Gas LLC | Katy, TX 77494 | Oil & Gas Operator | Jul 2026 |
| 174 | Century Production Inc | | Oil & Gas Operator | Dec 1986 |
| 175 | CH4 Energy LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2006 |
| 176 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | Jun 2026 |
| 177 | Chambers Jerry | Denver, CO 80237 | Oil & Gas Operator | Dec 1993 |
| 178 | Chancellor & Dolezal | | Gas Operator | Apr 1992 |
| 179 | Chandler Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2009 |
| 180 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Sep 2026 |
| 181 | Chaparral Resources Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 1996 |
| 182 | Chapman Exploration Inc | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2013 |
| 183 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 184 | Charger Resources, LLC | Hurst, TX 76054 | Oil & Gas Operator | Aug 2015 |
| 185 | Cheetah Oil Inc | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 186 | Chemily Management Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2023 |
| 187 | Cherokee Oil Production Inc | Wichita, KS 67230 | Oil & Gas Operator | Jan 1997 |
| 188 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Sep 2026 |
| 189 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Sep 2026 |
| 190 | Cheyenne River LLC | Dallas, TX 75204 | Oil & Gas Operator | Nov 2018 |
| 191 | Chipcore LLC | Casper, WY 82601 | Oil & Gas Operator | Jul 2026 |
| 192 | Chippewa Oil & Gas Inc | Douglas, WY 82633 | Oil & Gas Operator | Jan 1985 |
| 193 | Chriscor Oil & Gas | Plana, TX 75075 | Oil & Gas Operator | Jul 1987 |
| 194 | Christensen C G | | Oil Operator | Sep 1990 |
| 195 | Christensen Ranch | Newcastle, WY 82701 | Oil Operator | Feb 2026 |
| 196 | Christmann John J | Lubbock, TX 79401 | Oil & Gas Operator | Dec 1994 |
| 197 | CHS McPherson Refinery Inc | Platteville, CO 80651 | Oil & Gas Operator | Apr 1994 |
| 198 | Cig Exploration | Denver, CO 80201 | Oil & Gas Operator | Sep 1999 |
| 199 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Apr 2026 |
| 200 | Cinco Natural Resources Corp | La Grange, TX 78945 | Oil & Gas Operator | Sep 2026 |