| 1001 | Conoco Incorpora | | Oil & Gas Operator | Apr 1988 |
| 1002 | Conrade Patsy | | Oil Operator | Jan 1986 |
| 1003 | Considine, Barry | Burrton, KS 67020 | Gas Operator | Mar 2025 |
| 1004 | Consolidated Gas & Energy Corp. | San Diego, CA 92130 | Oil Operator | Apr 2012 |
| 1005 | Consolidated Oil | | Oil Operator | Jul 1996 |
| 1006 | Consolidated Oil & Gas Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2012 |
| 1007 | Consolidated Oil Well Services, Inc | Chanute, KS 66720 | Oil Operator | Jan 2008 |
| 1008 | Continental Brok | | Oil Operator | Oct 1994 |
| 1009 | Continental Ener | | Oil & Gas Operator | Dec 1996 |
| 1010 | Continental Energy | Garden City, KS 67846-0918 | Oil & Gas Operator | Jul 2017 |
| 1011 | Continental Expl | | Oil Operator | Sep 1991 |
| 1012 | Continental Oil | | Oil Operator | Jun 1985 |
| 1013 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 1014 | Continental Resources, Inc. | Oklahoma City, OK 73126 | Oil & Gas Operator | Feb 2026 |
| 1015 | Continuum Midstream, LLC | Tulsa, OK 74136 | Oil Operator | Aug 2025 |
| 1016 | Convest Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Sep 2014 |
| 1017 | Cook Operating C | | Oil Operator | May 1987 |
| 1018 | Cook, James A. | Augusta, KS 67010 | Oil Operator | Jul 1997 |
| 1019 | Cooke, Donald E./Lee Wanda | Coffeyville, KS 67331 | Oil Operator | Dec 2001 |
| 1020 | Cooper Oil Company | Andover, KS 67002 | Oil Operator | Oct 1997 |
| 1021 | Cooper Service Co. | | Oil & Gas Operator | Sep 2025 |
| 1022 | Cooper, J. M. | Winfield, KS 67119 | Oil Operator | Oct 1997 |
| 1023 | Cooper, Lowell E. | Peabody, KS 66866 | Oil Operator | Nov 1987 |
| 1024 | Copperhead Creek Enterprises, Inc. | Chautauqua, KS 67334 | Oil Operator | Sep 2019 |
| 1025 | Copperhead Oil | Colony, KS 66015 | Oil Operator | Sep 1985 |
| 1026 | Coral Coast Petroleum, L.C. | Wichita, KS 67226 | Oil & Gas Operator | Nov 2019 |
| 1027 | Coral Production Corporation | Denver, CO 80201 | Oil & Gas Operator | Sep 2025 |
| 1028 | Corie Oil Co., Inc. | Russell, KS 67665 | Oil Operator | Feb 2003 |
| 1029 | Corie Oil Compan | | Oil Operator | Jul 1985 |
| 1030 | Corlena Oil Company | Amarillo, TX 79101 | Oil & Gas Operator | Feb 2026 |
| 1031 | Cornell Rich M - | | Oil & Gas Operator | May 1993 |
| 1032 | Coronado Kansas, LLC | Tulsa, OK 74133 | Oil Operator | Oct 2009 |
| 1033 | Coronado Oil | Lindsborg, KS 67456 | Oil Operator | Sep 1985 |
| 1034 | Coronado Oil & G | | Oil Operator | Dec 1996 |
| 1035 | Coronado Oil & Gas, Inc. | Great Bend, KS 67530 | Oil Operator | Jul 2004 |
| 1036 | Coronado Oil, Inc. | Salina, KS 67401 | Oil Operator | May 1990 |
| 1037 | Corsair Energy, LC | Wichita, KS 67202 | Oil & Gas Operator | Apr 2004 |
| 1038 | Cortam, Inc. | Augusta, KS 67010 | Oil Operator | Dec 2024 |
| 1039 | Corwin B V | Enid, OK 73701 | Oil & Gas Operator | Apr 2017 |
| 1040 | Costilla Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Mar 2015 |
| 1041 | Cotton Petroleum | | Oil & Gas Operator | May 1988 |
| 1042 | Cottonwood Oil C | | Oil & Gas Operator | Oct 1988 |
| 1043 | Cougar Energies, Inc. | Oberlin, KS 67749 | Oil Operator | Jun 1996 |
| 1044 | Cowboy Oil & Gas | Bristow, OK 74010-0057 | Oil & Gas Operator | Jul 2018 |
| 1045 | Cowley Energy Associates, LLC | Plano, TX 75093 | Gas Operator | Dec 2009 |
| 1046 | Cox Edwin L & Be | | Oil & Gas Operator | Nov 1989 |
| 1047 | Cox Exploration | Cherryvale, KS 67335 | Gas Operator | Aug 1989 |
| 1048 | Cox, Wayne D. | Eureka, KS 67045 | Oil Operator | Sep 1991 |
| 1049 | Craig Oil Compan | | Oil Operator | Jul 1996 |
| 1050 | Craig Oil Company | | Oil Operator | Dec 2019 |
| 1051 | Craig-Stephfield | | Oil & Gas Operator | Jan 1994 |
| 1052 | Craig/Stephfield Oil & Gas, Inc. | Ponca City, OK 74602 | Oil & Gas Operator | Apr 2001 |
| 1053 | Crane Edward | | Oil Operator | Feb 1995 |
| 1054 | Crater, Gary D. | Kansas City, MO 64108 | Oil & Gas Operator | Feb 1988 |
| 1055 | Crawford Oil & W | | Oil Operator | Dec 1985 |
| 1056 | Crawford Oil Com | | Oil Operator | Dec 1987 |
| 1057 | Crawford Oil LLC | Paola, KS 66071 | Oil Operator | Dec 2019 |
| 1058 | Crawford Production Company Inc | Junction City, AR 71749 | Oil & Gas Operator | Sep 2025 |
| 1059 | Crazy Horse Oil | | Oil Operator | May 2025 |
| 1060 | Creco Operating LLC | | Oil & Gas Operator | Nov 2015 |
| 1061 | Crescent Drillin | | Gas Operator | Apr 1991 |
| 1062 | Crescent Oil & Gas | Decatur, TX 76234 | Gas Operator | Dec 1999 |
| 1063 | Crest Petr Inc | Rose Hill, KS 67133 | Oil Operator | Jun 2000 |
| 1064 | Crest Petroleum | Newark, OH 43055 | Oil & Gas Operator | Nov 1993 |
| 1065 | Criger Oil Compa | | Oil Operator | Sep 1992 |
| 1066 | Crimson Resources, LLC | Tulsa, OK 74133 | Oil Operator | Jul 2007 |
| 1067 | Cris Oil | | Oil Operator | May 2025 |
| 1068 | Criteria Petrole | | Oil Operator | Sep 1996 |
| 1069 | Crockett Oil And Gas, Inc. | Sharon, KS 67138 | Oil & Gas Operator | Jun 2006 |
| 1070 | Cross And Cross | Overland Park, KS 66214 | Oil Operator | Sep 1997 |
| 1071 | Cross Bar Energy, LLC | Wichita, KS 67206 | Oil Operator | Sep 2025 |
| 1072 | Cross Bar Petrol | | Oil Operator | Aug 1995 |
| 1073 | Cross Bar Petroleum, Inc. | Wichita, KS 67205 | Oil & Gas Operator | Jun 2016 |
| 1074 | Cross Timbers Op | | Oil & Gas Operator | Nov 1996 |
| 1075 | Cross Timbers Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2025 |
| 1076 | Crossfield Larry | | Oil & Gas Operator | Sep 1993 |
| 1077 | Crowe Drilling C | | Oil & Gas Operator | May 1995 |
| 1078 | Crown Consulting Inc | Liberal, KS 67905 | Oil & Gas Operator | Sep 2025 |
| 1079 | Crown Energy Company | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2025 |
| 1080 | Crown Well Service Inc | Capon Bridge, WV 26711 | Oil Operator | Sep 2025 |
| 1081 | Crude Kin Oil Company, Inc. | Louisburg, KS 66053 | Oil Operator | Sep 2025 |
| 1082 | Crude Producers | | Oil & Gas Operator | Sep 1988 |
| 1083 | CTR 247 LLC | Peru, KS 67360 | Oil Operator | Jul 2025 |
| 1084 | Cudd Operating Corp | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2020 |
| 1085 | Culbreath Oil & Gas Co Inc | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2025 |
| 1086 | Cullen Corporati | | Oil & Gas Operator | Jan 1993 |
| 1087 | Cullison, Jimmie I. | Moscow, KS 67952 | Oil Operator | Apr 2002 |
| 1088 | Culver & Grounds | | Oil & Gas Operator | Nov 1995 |
| 1089 | Culver & Grounds Oil Properties, Inc. | McPherson, KS 67460 | Oil Operator | Sep 2025 |
| 1090 | Cunningham Crude, A General Partnership | Independence, KS 67301 | Oil Operator | Sep 2025 |
| 1091 | Cunningham, Melvin | Medicine Lodge, KS 67104 | Oil Operator | Jan 2013 |
| 1092 | Curry Oil | | Oil Operator | May 2005 |
| 1093 | Curry, Gregg | Madison, KS 66860 | Oil Operator | Sep 2025 |
| 1094 | Curt'S Oil Opera | | Oil Operator | Nov 1994 |
| 1095 | Curt'S Oil Operation, LLC | Hoisington, KS 67544 | Oil & Gas Operator | Sep 2025 |
| 1096 | Custom Oil Explo | | Oil & Gas Operator | May 1992 |
| 1097 | Custom Service LLC | St John, KS 67576 | Oil Operator | Sep 2025 |
| 1098 | Cutler Oil, LLC | Rantoul, KS 66079 | Oil Operator | Sep 2025 |
| 1099 | CWB Oil Company, LLC | St. Francis, KS 67756 | Oil Operator | Sep 2025 |
| 1100 | Cycle Oil & Gas LTD | | Gas Operator | Sep 2025 |