| 201 | Brown Operating Inc | Casper, WY 82602 | Oil & Gas Operator | May 2019 |
| 202 | Brown Shirley | Buffalo, WY 82834 | Oil & Gas Operator | Oct 2010 |
| 203 | Brown Tom Inc | Dallas, TX 75240 | Oil & Gas Operator | Mar 2015 |
| 204 | Bta Oil Producers, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 205 | Buchanan Wayman W | San Antonio, TX 78212 | Oil & Gas Operator | Sep 1990 |
| 206 | Buck Creek Freight Inc | Lusk, WY 82225 | Oil Operator | Jun 2025 |
| 207 | Buffalo Resources LLC | Woodward, OK 73801 | Oil & Gas Operator | May 2025 |
| 208 | Bullock A O | Casper, WY 82604 | Oil & Gas Operator | May 2025 |
| 209 | Bullock Gladys C Trust | | Oil & Gas Operator | Dec 1999 |
| 210 | Bummer Bruce L | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 211 | Bunkirt J J Oil & Gas Corporation | Powell, WY 82435 | Oil & Gas Operator | Jun 2025 |
| 212 | Burk Royalty Co., LTD. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 213 | Burlington Resources Oil & Gas Company L | Gillette, WY 82718 | Oil & Gas Operator | Jan 2022 |
| 214 | Burnett Oil Co Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 215 | Burr Oil & Gas Inc | Farmington, NM 87499 | Oil & Gas Operator | Oct 2019 |
| 216 | Butler Oil Co | Casper, WY 82602 | Oil & Gas Operator | Dec 1996 |
| 217 | BW Oil LLC | Hamel, MN 55340 | Oil Operator | Jun 2015 |
| 218 | Bwab Incorporated | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 219 | BXP Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jul 2025 |
| 220 | Byron Oil Industries Inc | Ballwin, MO 63011 | Oil & Gas Operator | Apr 2019 |
| 221 | C & H Well Servicing Inc | Gillette, WY 82717 | Oil & Gas Operator | Jun 2025 |
| 222 | C & K Petroleum | | Oil & Gas Operator | Jan 1984 |
| 223 | C And M Oil Inc | Kimball, NE 69145 | Oil & Gas Operator | Dec 2024 |
| 224 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 225 | Caerus Northern Rockies LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2021 |
| 226 | Calco Inc | | Oil & Gas Operator | Feb 1991 |
| 227 | Callaway Oil & Gas LLC | Gillette, WY 82717 | Oil & Gas Operator | Apr 2025 |
| 228 | Cambria Oil Company | Casper, WY 82601 | Oil & Gas Operator | Dec 1996 |
| 229 | Camwest II LP | McKinney, TX 75070 | Oil & Gas Operator | Jul 2007 |
| 230 | Camwest Limited Partnership | Denver, CO 80202 | Oil & Gas Operator | Apr 2004 |
| 231 | Capitan Operating LLC | Reno, NV 89502 | Oil & Gas Operator | Jan 2013 |
| 232 | Capitol Oil & Gas Corporation | Centennial, WY 82055 | Oil Operator | Feb 2006 |
| 233 | Carbon Creek Energy LLC | Sheridan, WY 82801 | Oil & Gas Operator | May 2025 |
| 234 | Cardinal Wyoming LLC | | Oil & Gas Operator | May 2025 |
| 235 | Carlson Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 236 | Carol-Holly Oil Corporation | Denver, CO 80237 | Oil & Gas Operator | Jun 2025 |
| 237 | Carrizo Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 238 | Castle Exploration Company Inc | Blue Bell, PA 19422 | Oil & Gas Operator | May 2018 |
| 239 | Castle Rock Oil LLC | | Oil Operator | Jun 2025 |
| 240 | Cat Oil | Byron, WY 82412 | Oil Operator | May 2001 |
| 241 | Caza Exploration Company | | Oil Operator | Nov 1991 |
| 242 | CCRP Operating Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2024 |
| 243 | CDX Gas, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2009 |
| 244 | Cedar Resources Corporation | Gillette, WY 82717 | Gas Operator | Dec 2010 |
| 245 | Cedar Ridge Operating Co LLC | Durango, CO 81303 | Gas Operator | Dec 2009 |
| 246 | Celeron Oil & Gas Company | | Oil & Gas Operator | Dec 1987 |
| 247 | Celsius Energy Company | Denver, CO 80202-1558 | Oil & Gas Operator | Mar 2000 |
| 248 | Cenergy Resources LLC | | Oil & Gas Operator | May 2025 |
| 249 | Cenex | | Oil & Gas Operator | Dec 1996 |
| 250 | Centennial Energy | Thermopolis, WY 82443 | Oil & Gas Operator | Apr 2025 |
| 251 | Central Operating Inc | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 252 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 253 | Central Wyoming Resources LTD | Glenrock, WY 82637 | Oil Operator | Jul 2021 |
| 254 | Century Energy | Gillette, WY 82717 | Oil & Gas Operator | Dec 1996 |
| 255 | Century Oil & Gas Corporation | | Oil & Gas Operator | Dec 1987 |
| 256 | Century Oil And Gas LLC | Katy, TX 77494 | Oil & Gas Operator | May 2025 |
| 257 | Century Production Inc | | Oil & Gas Operator | Dec 1986 |
| 258 | CH4 Energy LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2006 |
| 259 | Chaco Energy Company | Denver, CO 80201 | Oil & Gas Operator | May 2025 |
| 260 | Chambers Jerry | Denver, CO 80237 | Oil & Gas Operator | Dec 1993 |
| 261 | Chancellor & Dolezal | | Gas Operator | Apr 1992 |
| 262 | Chandler Energy LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2009 |
| 263 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Jul 2025 |
| 264 | Chaparral Resources Inc | Denver, CO 80293 | Oil & Gas Operator | Jan 1996 |
| 265 | Chapman Exploration Inc | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2013 |
| 266 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 267 | Charger Resources, LLC | Hurst, TX 76054 | Oil & Gas Operator | Aug 2015 |
| 268 | Cheetah Oil Inc | Casper, WY 82602 | Oil & Gas Operator | Dec 2007 |
| 269 | Chemily Management Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2023 |
| 270 | Cherokee Oil Production Inc | Wichita, KS 67230 | Oil & Gas Operator | Jan 1997 |
| 271 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | Jul 2025 |
| 272 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 273 | Cheyenne River LLC | Dallas, TX 75204 | Oil & Gas Operator | Nov 2018 |
| 274 | Chipcore LLC | Casper, WY 82601 | Oil & Gas Operator | May 2025 |
| 275 | Chippewa Oil & Gas Inc | Douglas, WY 82633 | Oil & Gas Operator | Jan 1985 |
| 276 | Chriscor Oil & Gas | Plana, TX 75075 | Oil & Gas Operator | Jul 1987 |
| 277 | Christensen C G | | Oil Operator | Sep 1990 |
| 278 | Christensen Ranch | Newcastle, WY 82701 | Oil Operator | Aug 2021 |
| 279 | Christmann John J | Lubbock, TX 79401 | Oil & Gas Operator | Dec 1994 |
| 280 | CHS McPherson Refinery Inc | Platteville, CO 80651 | Oil & Gas Operator | Apr 1994 |
| 281 | Cig Exploration | Denver, CO 80201 | Oil & Gas Operator | Sep 1999 |
| 282 | Cimarex Energy Co | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 283 | Cinco Natural Resources Corp | La Grange, TX 78945 | Oil & Gas Operator | Jul 2025 |
| 284 | Ciris Energy Inc | Centennial, CO 80112 | Gas Operator | Dec 2016 |
| 285 | Cirque Resources LP | Denver, CO 80202 | Oil & Gas Operator | Aug 2016 |
| 286 | Citation Oil & Gas Corp. | Houston, TX 77269 | Oil & Gas Operator | Jul 2025 |
| 287 | CKT Energy LLC | Dallas, TX 75379 | Oil & Gas Operator | Sep 2020 |
| 288 | Clark Oil & Gas Inc | | Oil & Gas Operator | Dec 1990 |
| 289 | Clark Oil Producing Company | | Oil & Gas Operator | Oct 1979 |
| 290 | CLC Operations Inc | Midland, TX 79701 | Oil & Gas Operator | Mar 1997 |
| 291 | Cline Production Company | Billings, MT 59104 | Oil & Gas Operator | May 2025 |
| 292 | Clinton Oil Company | Wichita, KS 67202 | Oil & Gas Operator | Apr 1980 |
| 293 | Cloud Peak Operating LLC | Casper, WY 82601 | Oil Operator | Apr 2025 |
| 294 | CMS Oil And Gas Company | Jackson, MI 49201 | Oil & Gas Operator | Oct 2002 |
| 295 | CNX Gas Company LLC | Canonsburg, PA 15317 | Oil & Gas Operator | May 2025 |
| 296 | Coal Creek Minerals LLC | Northglenn, CO 80234 | Gas Operator | Feb 2012 |
| 297 | Coaleum Corporation | Dallas, TX 75205 | Oil & Gas Operator | Jan 2001 |
| 298 | Coastal Chem Inc | Midvale, UT 84047 | Oil & Gas Operator | Aug 2003 |
| 299 | Coastal Oil & Gas Corporation | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 300 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |