| 901 | CK Oil & Gas LLC | Herington, KS 67449 | Oil & Gas Operator | Mar 2025 |
| 902 | Cla-Mar Oil Company, LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 903 | Claassen Oil And Gas Inc | Estes Park, CO 80517 | Oil & Gas Operator | Sep 2025 |
| 904 | Claibourn, Darrel R. | Neodesha, KS 66757 | Oil Operator | Oct 2011 |
| 905 | Clair Oil, Inc. | Russell, KS 67665 | Oil Operator | Nov 2019 |
| 906 | Clapp Oil LLC | | Oil Operator | Sep 2025 |
| 907 | Clarco Gas Co., Inc. | Westmont, IL 60559 | Oil Operator | Dec 2011 |
| 908 | Clark B & Cahoj | | Oil Operator | Apr 1995 |
| 909 | Clark Energy, LLC | Chanute, KS 66720 | Oil & Gas Operator | Jun 2022 |
| 910 | Clark Exploratio | | Oil & Gas Operator | Jun 1991 |
| 911 | Clark Exploration Company | Highlands Ranch, CO 80126-7645 | Oil & Gas Operator | Nov 2024 |
| 912 | Clark Oil, LLC | Wellsville, KS 66092 | Oil Operator | Apr 2022 |
| 913 | Clark Operating Services Inc | Okmulgee, OK 74447 | Oil & Gas Operator | May 2013 |
| 914 | Clark, Daryl | Phillipsburg, KS 67661 | Oil Operator | Aug 2025 |
| 915 | Clark, Robert A. | Wichita, KS 67202 | Gas Operator | Jul 1990 |
| 916 | Clarke Corporati | Medicine Lodge, KS 67104 | Oil & Gas Operator | Sep 2025 |
| 917 | Class Oil | Hays, KS 67601 | Oil Operator | Jun 1991 |
| 918 | Classic Well Service, Inc. | Claflin, KS 67525 | Oil Operator | Dec 2019 |
| 919 | Clausing, Garry | Coffeyville, KS 67337 | Oil Operator | Apr 2024 |
| 920 | Claussen Roy A & | | Oil Operator | Jun 1986 |
| 921 | Clawson, Merle Eugene | McCune, KS 66753 | Oil Operator | Nov 2016 |
| 922 | Clayton Corp Petro & NTRL Gas Prodn | Lakewood, CO 80228 | Oil & Gas Operator | Dec 2009 |
| 923 | Clayton Corporat | | Oil & Gas Operator | Jun 1994 |
| 924 | Clayton Corporation | Golden, CO 80401 | Oil & Gas Operator | Dec 2019 |
| 925 | Clear Creek Exploration LLC | Fredonia, KS 66736 | Gas Operator | Apr 2011 |
| 926 | Cleary Petroleum Corporation | Edmond, OK 73083 | Oil & Gas Operator | Jul 2019 |
| 927 | Cleaver Loraine | | Oil Operator | Dec 1996 |
| 928 | Cleaver, Loraine G. (Deceased) Estate | Iola, KS 66749 | Oil Operator | Nov 2009 |
| 929 | Clifford Resourc | | Oil & Gas Operator | Mar 1989 |
| 930 | Clinton Bowers Estate | Manhatten, KS 66502 | Oil Operator | Dec 1998 |
| 931 | Clinton Producti | | Oil Operator | Dec 1989 |
| 932 | Clinton Production, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Aug 2025 |
| 933 | Clinton, Orville L., Jr. | Paola, KS 66071 | Oil Operator | Apr 2005 |
| 934 | Clothier, David W. | Eastborough, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 935 | Clover Oil Company | | Oil Operator | Sep 2025 |
| 936 | Clubine, Jim L. | Independence, KS 67301 | Oil Operator | Aug 2025 |
| 937 | Clute Oil Corporation | Cherry Hills VIllage, CO 80113 | Oil & Gas Operator | Sep 2025 |
| 938 | Clyde Petroleum | | Oil & Gas Operator | Dec 1988 |
| 939 | CM Oil Co. | FT Stockton, TX 79735 | Oil & Gas Operator | Feb 2026 |
| 940 | CMX, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 941 | CNG Producing | New Orleans, LA 70112-6000 | Oil & Gas Operator | Jun 2000 |
| 942 | Co-Co Incorporat | | Oil Operator | Oct 1989 |
| 943 | Coachman Energy Operating Co, LLC | Englewood, CO 80111 | Oil Operator | May 2024 |
| 944 | Coal Creek Energy, LLC | Overland Park, KS 66221 | Oil Operator | Dec 2019 |
| 945 | Coastal Oil & Ga | | Oil & Gas Operator | Oct 1996 |
| 946 | Coastal Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 947 | Coastal Oil & Gas Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2009 |
| 948 | Coats Energy, Inc. | Wichita, KS 67201 | Oil & Gas Operator | Sep 2025 |
| 949 | Cobalt Energy LLC | Wichita, KS 67202 | Oil & Gas Operator | Sep 2025 |
| 950 | Cobra Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 951 | Cobra Oil & Gas Corporation | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 952 | Coda Energy, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1998 |
| 953 | Cody & Krysti Hunsperger | Osawatomie, KS 66064 | Oil Operator | Mar 2024 |
| 954 | Cody Resources, Inc. | Midland, TX 79705 | Oil & Gas Operator | Sep 2002 |
| 955 | Cody, Ken L. | Longton, KS 67352 | Oil & Gas Operator | Sep 2025 |
| 956 | Cody, Nancy M. | Fredonia, KS 66736 | Oil Operator | Jun 1998 |
| 957 | Coen Energy | | Oil Operator | Mar 1995 |
| 958 | Coen Energy Corporation | Overland Park, KS 66221 | Oil Operator | Sep 2025 |
| 959 | Cokan Resources | Colby, KS 67701 | Oil Operator | Aug 1994 |
| 960 | Col-Kan Developm | | Oil & Gas Operator | Jan 1995 |
| 961 | Col-Kan Development, Inc. | Russell, KS 67665 | Oil Operator | Jul 2005 |
| 962 | Collier Oil Prop | | Oil Operator | Apr 1987 |
| 963 | Collins John B | | Oil Operator | Sep 1994 |
| 964 | Collins Oil Co. | Bartlesville, OK 74006 | Oil & Gas Operator | Dec 2024 |
| 965 | Collins Oil Comp | | Oil Operator | Apr 1995 |
| 966 | Collins Oil, LLC | Ellinwood, KS 67526 | Oil Operator | Sep 2025 |
| 967 | Colonial Corporation | St Simons Island, GA 31522 | Oil & Gas Operator | Dec 2000 |
| 968 | Colorado Crude E | | Oil Operator | Jan 1986 |
| 969 | Colorado Interst | | Gas Operator | Aug 1995 |
| 970 | Colorado Interstate Gas Company LLC | Colorado Springs, CO 80944 | Oil & Gas Operator | Dec 2025 |
| 971 | Colorado Oil & G | | Oil & Gas Operator | Oct 1987 |
| 972 | Colt Energy Inc | Iola, KS 66749 | Oil & Gas Operator | Sep 2025 |
| 973 | Colt Energy Inco | | Oil & Gas Operator | Dec 1996 |
| 974 | Colt Oil Company | Andrews, TX 79714 | Oil & Gas Operator | Feb 1996 |
| 975 | Colt Resources Corporation | Billings, MT 59103 | Oil & Gas Operator | Feb 2013 |
| 976 | Columbia Petrole | | Oil Operator | Sep 1988 |
| 977 | Columbian Production Corporation | Topeka, KS 66601 | Oil Operator | Oct 1999 |
| 978 | Columbian Servic | | Oil & Gas Operator | Nov 1993 |
| 979 | Columbian Services C | | Oil Operator | Jan 1992 |
| 980 | Columbian Services Corporation | Topeka, KS 66603 | Gas Operator | Dec 2009 |
| 981 | Comanche Product | | Oil & Gas Operator | Jan 1992 |
| 982 | Comanche Production, Inc. | Longview, TX 75606 | Oil & Gas Operator | Jan 2006 |
| 983 | Comanche Resources Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Dec 2025 |
| 984 | Commercial Energ | | Gas Operator | Oct 1996 |
| 985 | Commercial Oil - | | Oil Operator | Apr 1994 |
| 986 | Commercial Oil Company, Inc. | Wichita, KS 67204 | Oil Operator | Jun 2001 |
| 987 | Commonwealth Pet | | Oil & Gas Operator | Nov 1995 |
| 988 | Compressor Syste | | Oil Operator | May 1991 |
| 989 | Conch Oil, Inc. | Wichita, KS 67202 | Oil Operator | Jun 2002 |
| 990 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 991 | Concorde Resources Corporation | Eufaula, OK 74432 | Oil & Gas Operator | Nov 2025 |
| 992 | Condor Energy | | Oil Operator | Aug 1995 |
| 993 | Condor Energy, Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Oct 2021 |
| 994 | Condor Petroleum | | Oil & Gas Operator | Nov 1990 |
| 995 | Condry Oil Compa | | Oil Operator | May 1992 |
| 996 | Conley, Harry | Colony, KS 66015 | Oil Operator | Aug 2025 |
| 997 | Connell, Mark Allen | Claflin, KS 67525 | Oil Operator | Sep 2025 |
| 998 | Conner, Eugene | Bartlesville, OK 74005 | Oil & Gas Operator | Jul 2020 |
| 999 | Conner, Rick | Winfield, KS 67156 | Oil Operator | Aug 2019 |
| 1000 | Conoco Inc | Houston, TX 77252 | Oil & Gas Operator | Mar 2015 |