| 6201 | Colorado Interstate Gas Co | Colorado Springs, CO 80944 | Oil & Gas Operator | Jul 2004 |
| 6202 | Colorado Interstate Gas Company LLC | Colorado Springs, CO 80944 | Oil & Gas Operator | Aug 2025 |
| 6203 | Colorado Oil & G | | Oil & Gas Operator | Oct 1987 |
| 6204 | Colorado Oil & Gas Corporation | | Oil & Gas Operator | May 2003 |
| 6205 | Colorado Oil Co., Inc. | | Oil & Gas Operator | Dec 1977 |
| 6206 | Colorado Pica Petro Corp | Cortez, CO 81321 | Oil & Gas Operator | Apr 2007 |
| 6207 | Colorado-Swanson Landing Oil & Gas, LLC | Kilgore, TX 75663 | Oil Operator | Oct 2025 |
| 6208 | Colotex Operating, LLC | Aurora, CO 80015 | Oil & Gas Operator | Oct 2025 |
| 6209 | Colpitt Brothers Oil | Collinsville, OK 74021 | Oil & Gas Operator | Apr 2020 |
| 6210 | Colpitt Brothers Operating Co | Collinsville, OK 74021 | Oil & Gas Operator | Jun 2025 |
| 6211 | Colpitt C H Drilling Co LLC | Collinsville, OK 74021-7107 | Oil Operator | Jun 2025 |
| 6212 | Colpitt Chas H Drilling Co | Collinsville, OK 74021-7105 | Oil & Gas Operator | Mar 2012 |
| 6213 | Colt Energy Inc | Iola, KS 66749 | Oil & Gas Operator | Jun 2025 |
| 6214 | Colt Energy Inco | | Oil & Gas Operator | Dec 1996 |
| 6215 | Colt Oil & Gas Co. | Abilene, TX 79601 | Oil Operator | Apr 2004 |
| 6216 | Colt Oil Company | Andrews, TX 79714 | Oil & Gas Operator | Feb 1996 |
| 6217 | Colt Oil Corporation | Smithville, WV 26178 | Oil & Gas Operator | Dec 2021 |
| 6218 | Colt Oil LLC | Sapulpa, OK 74066-1010 | Oil Operator | Jun 2025 |
| 6219 | Colt Production Corp. Inc. | | Oil & Gas Operator | Jul 1996 |
| 6220 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 6221 | Colter Operating Co | Horseshoe Bay, TX 78654 | Oil & Gas Operator | Nov 1997 |
| 6222 | Coltharp, Edward H | | Oil & Gas Operator | Dec 1970 |
| 6223 | Colton Limited Liability Co | | Oil & Gas Operator | Sep 2023 |
| 6224 | Coltrane Charles | | Oil Operator | Dec 1980 |
| 6225 | Columbia Energy Properties, Inc. | Baytown, TX 77521 | Oil & Gas Operator | Jul 2004 |
| 6226 | Columbia Gas Dev. Corp. | | Oil & Gas Operator | Apr 1996 |
| 6227 | Columbia Gas Development | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 6228 | Columbia Gas Development Corp. | Houston, TX 77251 | Oil & Gas Operator | Jun 1996 |
| 6229 | Columbia Gas Trans LLC | Charleston, WV 25325-1273 | Gas Operator | Dec 1987 |
| 6230 | Columbia Gas Transmission, LLC | Charleston, WV 25314 | Oil & Gas Operator | Dec 2021 |
| 6231 | Columbia Gulf Transmission Co. | | Oil Operator | Dec 2014 |
| 6232 | Columbia Gulf Transmission Company, LLC | | Oil Operator | Jan 2025 |
| 6233 | Columbia Minerals Corp., Inc. | | Oil & Gas Operator | May 1996 |
| 6234 | Columbia Natural Res Inc | Charleston, WV 25362-0070 | Gas Operator | Dec 2008 |
| 6235 | Columbia Natural Resources, LLC | Charleston, WV 23502 | Oil & Gas Operator | Dec 2021 |
| 6236 | Columbia Oil Company, Inc | Guy, AR 72061 | Oil & Gas Operator | Jan 2025 |
| 6237 | Columbia Petrole | | Oil Operator | Sep 1988 |
| 6238 | Columbia Petroleum Corp. | | Oil & Gas Operator | Jun 1982 |
| 6239 | Columbia Petroleum LLC | Oyster Bay, NY 11771 | Oil & Gas Operator | Feb 2025 |
| 6240 | Columbia Petroleum, LTD. | Farmington, UT 84025 | Oil Operator | Jul 2025 |
| 6241 | Columbia Production Company | Edmond, OK 73083 | Oil & Gas Operator | May 2020 |
| 6242 | Columbian Production Corporation | Topeka, KS 66601 | Oil Operator | Oct 1999 |
| 6243 | Columbian Servic | | Oil & Gas Operator | Nov 1993 |
| 6244 | Columbian Services C | | Oil Operator | Jan 1992 |
| 6245 | Columbian Services Corporation | Topeka, KS 66603 | Gas Operator | Dec 2009 |
| 6246 | Columbine Associates | | Oil & Gas Operator | Aug 2025 |
| 6247 | Columbine Exploration Corp | Englewood, CO 80111 | Oil & Gas Operator | Aug 1998 |
| 6248 | Columbus Energy Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2008 |
| 6249 | Columbus Energy, LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 6250 | Columbus III Production LC | | Oil Operator | Oct 2003 |
| 6251 | Columbus Oil And Gas LLC | | Oil Operator | Oct 2020 |
| 6252 | Columbus Oil Company | Seminole, OK 74868 | Oil & Gas Operator | Jul 2025 |
| 6253 | Columbus Oilfield Explor Co | Powell, OH 43065-9315 | Gas Operator | Dec 2004 |
| 6254 | Columbus Oilfield Exploration Company | Columbus, OH 43220 | Oil & Gas Operator | Dec 2013 |
| 6255 | Columbus Production Inc | | Oil & Gas Operator | Mar 2005 |
| 6256 | Comac Well Service, Inc. | Borger, TX 79008 | Oil & Gas Operator | Mar 2008 |
| 6257 | Comal Operating LLC | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 6258 | Comanche Drilling Company | Cut Bank, MT 59427 | Oil & Gas Operator | Jun 2025 |
| 6259 | Comanche Exploration Co LLC | Oklahoma City, OK 73116-7334 | Oil & Gas Operator | Jul 2025 |
| 6260 | Comanche Exploration Company | Oklahoma City, OK 73120-2797 | Oil & Gas Operator | Feb 2007 |
| 6261 | Comanche Oil & Gas Corp | Salt Lake City, UT 84107-3075 | Oil & Gas Operator | May 2005 |
| 6262 | Comanche Oil And Service, LLC | | Oil Operator | May 2025 |
| 6263 | Comanche Operating Co. | Oklahoma City, OK 73120 | Oil & Gas Operator | Aug 2002 |
| 6264 | Comanche Petroleum Corporation | Oklahoma City, OK 73179 | Oil & Gas Operator | Apr 2024 |
| 6265 | Comanche Product | | Oil & Gas Operator | Jan 1992 |
| 6266 | Comanche Production Co | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 1998 |
| 6267 | Comanche Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2006 |
| 6268 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 2025 |
| 6269 | Comanche Well Service Corp. | Plano, TX 75093 | Oil & Gas Operator | Oct 2025 |
| 6270 | Combest A L | Purcell, OK 73080-6829 | Oil & Gas Operator | Aug 2021 |
| 6271 | Combined Oil & Gas | Denver, CO 80202 | Oil & Gas Operator | Feb 1990 |
| 6272 | Combined Resources Corporation | Edmond, OK 73083 | Oil & Gas Operator | Oct 2025 |
| 6273 | Combs Production LLC | Depew, OK 74028-0483 | Oil & Gas Operator | Jun 2025 |
| 6274 | Combs, Steven H | Corydon, KY 42406 | Oil Operator | Dec 2023 |
| 6275 | Comco Of Louisiana, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2000 |
| 6276 | Comdisco Exploration Inc | | Oil Operator | Dec 1990 |
| 6277 | Comdisco Resources Inc | | Oil Operator | Aug 2004 |
| 6278 | Comerica Properties Corp | | Oil Operator | May 1985 |
| 6279 | Comet Energy Services LLC | Traverse City, MI 49686 | Oil & Gas Operator | Oct 2011 |
| 6280 | Comet Oil & Gas, Inc. | Conroe, TX 77305 | Oil & Gas Operator | Oct 2025 |
| 6281 | Comet Oil Company | Velma, OK 73091 | Oil & Gas Operator | May 2005 |
| 6282 | Comet Production | Conroe, TX 77305 | Oil Operator | Oct 2025 |
| 6283 | Comet-Haines Oil Company | Sulphur, OK 73086-0546 | Oil & Gas Operator | Mar 2013 |
| 6284 | Cometra Oil And Gas, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 6285 | Comgas Inc | Hebron, OH 43025-9716 | Oil & Gas Operator | Dec 1988 |
| 6286 | Comm Energy Inc | Weston, WV 26452-2907 | Gas Operator | Dec 2004 |
| 6287 | Command Energy Operating LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jun 2025 |
| 6288 | Commander Oil Company LTD. | | Oil & Gas Operator | Dec 2021 |
| 6289 | Commerce Energy Co | Cleveland, OH 44115 | Oil & Gas Operator | Dec 1987 |
| 6290 | Commerce Energy, Inc. | | Oil & Gas Operator | Dec 1999 |
| 6291 | Commerce Oil & Gas Co | Rocky River, OH 44116 | Oil & Gas Operator | Dec 1996 |
| 6292 | Commercial Energ | | Gas Operator | Oct 1996 |
| 6293 | Commercial Oil - | | Oil Operator | Apr 1994 |
| 6294 | Commercial Oil Company, Inc. | Wichita, KS 67204 | Oil Operator | Jun 2001 |
| 6295 | Commodore Energy Co | Rolling Hills, CA 90274-5265 | Oil & Gas Operator | Dec 2007 |
| 6296 | Common Energy Inc | Douglas, WY 82633 | Oil & Gas Operator | Aug 1995 |
| 6297 | Common Resources L.L.C. | The Woodlands, TX 77380 | Oil & Gas Operator | May 2010 |
| 6298 | Commonwealth Energy, Inc. | Weston, WV 26452-0000 | Oil & Gas Operator | Dec 2021 |
| 6299 | Commonwealth Pet | | Oil & Gas Operator | Nov 1995 |
| 6300 | Commonwealth Resources, LLC | Fort Collins, CO 80524 | Oil Operator | Dec 2008 |