| 201 | Cincris Energy C | | Oil & Gas Operator | Jun 1991 |
| 202 | Circle E Oil - E | | Oil Operator | May 1990 |
| 203 | Circle K Enterprises | | Oil & Gas Operator | Aug 2023 |
| 204 | Circle L Exploration | Independence, KS 67301 | Gas Operator | May 2015 |
| 205 | Circle T Oil | | Oil Operator | Nov 2024 |
| 206 | Cisco Operating LLC | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 207 | Citadel Oil LLC | Edmond, OK 73083 | Oil Operator | Sep 2025 |
| 208 | Citadel Prod Company Inc | Denver, CO 80201 | Oil Operator | Sep 1996 |
| 209 | Citation Energy | | Oil & Gas Operator | Jul 1993 |
| 210 | Citation Oil & G | | Oil & Gas Operator | Dec 1996 |
| 211 | Citation Oil & Gas Corp | Houston, TX 77269 | Oil & Gas Operator | Feb 2026 |
| 212 | City Of Chanute | Chanute, KS 66720 | Oil Operator | Feb 1994 |
| 213 | City Of Garden City, Kansas | Garden City, KS 67846 | Gas Operator | Sep 2025 |
| 214 | City Of Hugoton, Kansas | Hugoton, KS 67951 | Gas Operator | Aug 2025 |
| 215 | City Of Satanta | Satanta, KS 67870 | Gas Operator | Sep 2025 |
| 216 | CJ Oil Inc | Madison, KS 66860 | Oil Operator | Sep 2025 |
| 217 | CK Oil | | Oil Operator | Aug 2025 |
| 218 | CK Oil & Gas LLC | Herington, KS 67449 | Oil & Gas Operator | Mar 2025 |
| 219 | Cla-Mar Oil Company, LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 220 | Claassen Oil And Gas Inc | Estes Park, CO 80517 | Oil & Gas Operator | Sep 2025 |
| 221 | Claibourn, Darrel R. | Neodesha, KS 66757 | Oil Operator | Oct 2011 |
| 222 | Clair Oil, Inc. | Russell, KS 67665 | Oil Operator | Nov 2019 |
| 223 | Clapp Oil LLC | | Oil Operator | Sep 2025 |
| 224 | Clarco Gas Co., Inc. | Westmont, IL 60559 | Oil Operator | Dec 2011 |
| 225 | Clark B & Cahoj | | Oil Operator | Apr 1995 |
| 226 | Clark Energy, LLC | Chanute, KS 66720 | Oil & Gas Operator | Jun 2022 |
| 227 | Clark Exploratio | | Oil & Gas Operator | Jun 1991 |
| 228 | Clark Exploration Company | Highlands Ranch, CO 80126-7645 | Oil & Gas Operator | Nov 2024 |
| 229 | Clark Oil, LLC | Wellsville, KS 66092 | Oil Operator | Apr 2022 |
| 230 | Clark Operating Services Inc | Okmulgee, OK 74447 | Oil & Gas Operator | May 2013 |
| 231 | Clark, Daryl | Phillipsburg, KS 67661 | Oil Operator | Aug 2025 |
| 232 | Clark, Robert A. | Wichita, KS 67202 | Gas Operator | Jul 1990 |
| 233 | Clarke Corporati | Medicine Lodge, KS 67104 | Oil & Gas Operator | Sep 2025 |
| 234 | Class Oil | Hays, KS 67601 | Oil Operator | Jun 1991 |
| 235 | Classic Well Service, Inc. | Claflin, KS 67525 | Oil Operator | Dec 2019 |
| 236 | Clausing, Garry | Coffeyville, KS 67337 | Oil Operator | Apr 2024 |
| 237 | Claussen Roy A & | | Oil Operator | Jun 1986 |
| 238 | Clawson, Merle Eugene | McCune, KS 66753 | Oil Operator | Nov 2016 |
| 239 | Clayton Corp Petro & NTRL Gas Prodn | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2009 |
| 240 | Clayton Corporat | | Oil & Gas Operator | Jun 1994 |
| 241 | Clayton Corporation | Golden, CO 80401 | Oil & Gas Operator | Dec 2019 |
| 242 | Clear Creek Exploration LLC | Fredonia, KS 66736 | Gas Operator | Apr 2011 |
| 243 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 244 | Cleaver Loraine | | Oil Operator | Dec 1996 |
| 245 | Cleaver, Loraine G. (Deceased) Estate | Iola, KS 66749 | Oil Operator | Nov 2009 |
| 246 | Clifford Resourc | | Oil & Gas Operator | Mar 1989 |
| 247 | Clinton Bowers Estate | Manhatten, KS 66502 | Oil Operator | Dec 1998 |
| 248 | Clinton Producti | | Oil Operator | Dec 1989 |
| 249 | Clinton Production, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Aug 2025 |
| 250 | Clinton, Orville L., Jr. | Paola, KS 66071 | Oil Operator | Apr 2005 |
| 251 | Clothier, David W. | Eastborough, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 252 | Clover Oil Company | | Oil Operator | Sep 2025 |
| 253 | Clubine, Jim L. | Independence, KS 67301 | Oil Operator | Aug 2025 |
| 254 | Clute Oil Corporation | Cherry Hills VIllage, CO 80113 | Oil & Gas Operator | Sep 2025 |
| 255 | Clyde Petroleum | | Oil & Gas Operator | Dec 1988 |
| 256 | CM Oil Co. | FT Stockton, TX 79735 | Oil & Gas Operator | Feb 2026 |
| 257 | CMX, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 258 | CNG Producing | New Orleans, LA 70112-6000 | Oil & Gas Operator | Jun 2000 |
| 259 | Co-Co Incorporat | | Oil Operator | Oct 1989 |
| 260 | Coachman Energy Operating Co, LLC | Englewood, CO 80111 | Oil Operator | May 2024 |
| 261 | Coal Creek Energy, LLC | Overland Park, KS 66221 | Oil Operator | Dec 2019 |
| 262 | Coastal Oil & Ga | | Oil & Gas Operator | Oct 1996 |
| 263 | Coastal Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 264 | Coastal Oil & Gas Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 265 | Coats Energy, Inc. | Wichita, KS 67201 | Oil & Gas Operator | Sep 2025 |
| 266 | Cobalt Energy LLC | Wichita, KS 67202 | Oil & Gas Operator | Sep 2025 |
| 267 | Cobra Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 268 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 269 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 270 | Cody & Krysti Hunsperger | Osawatomie, KS 66064 | Oil Operator | Mar 2024 |
| 271 | Cody Resources, Inc. | Midland, TX 79705 | Oil & Gas Operator | Sep 2002 |
| 272 | Cody, Ken L. | Longton, KS 67352 | Oil & Gas Operator | Sep 2025 |
| 273 | Cody, Nancy M. | Fredonia, KS 66736 | Oil Operator | Jun 1998 |
| 274 | Coen Energy | | Oil Operator | Mar 1995 |
| 275 | Coen Energy Corporation | Overland Park, KS 66221 | Oil Operator | Sep 2025 |
| 276 | Cokan Resources | Colby, KS 67701 | Oil Operator | Aug 1994 |
| 277 | Col-Kan Developm | | Oil & Gas Operator | Jan 1995 |
| 278 | Col-Kan Development, Inc. | Russell, KS 67665 | Oil Operator | Jul 2005 |
| 279 | Collier Oil Prop | | Oil Operator | Apr 1987 |
| 280 | Collins John B | | Oil Operator | Sep 1994 |
| 281 | Collins Oil Co. | Bartlesville, OK 74006 | Oil & Gas Operator | Dec 2024 |
| 282 | Collins Oil Comp | | Oil Operator | Apr 1995 |
| 283 | Collins Oil, LLC | Ellinwood, KS 67526 | Oil Operator | Sep 2025 |
| 284 | Colonial Corporation | St Simons Island, GA 31522 | Oil & Gas Operator | Dec 2000 |
| 285 | Colorado Crude E | | Oil Operator | Jan 1986 |
| 286 | Colorado Interst | | Gas Operator | Aug 1995 |
| 287 | Colorado Interstate Gas Company LLC | Colorado Springs, CO 80944 | Oil & Gas Operator | Dec 2025 |
| 288 | Colorado Oil & G | | Oil & Gas Operator | Oct 1987 |
| 289 | Colt Energy Inc | Iola, KS 66749 | Oil & Gas Operator | Sep 2025 |
| 290 | Colt Energy Inco | | Oil & Gas Operator | Dec 1996 |
| 291 | Colt Oil Company | Andrews, TX 79714 | Oil & Gas Operator | Feb 1996 |
| 292 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 293 | Columbia Petrole | | Oil Operator | Sep 1988 |
| 294 | Columbian Production Corporation | Topeka, KS 66601 | Oil Operator | Oct 1999 |
| 295 | Columbian Servic | | Oil & Gas Operator | Nov 1993 |
| 296 | Columbian Services C | | Oil Operator | Jan 1992 |
| 297 | Columbian Services Corporation | Topeka, KS 66603 | Gas Operator | Dec 2009 |
| 298 | Comanche Product | | Oil & Gas Operator | Jan 1992 |
| 299 | Comanche Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2006 |
| 300 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Dec 2025 |