| 3101 | North American Drilling & Exploration, Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Aug 2015 |
| 3102 | North American Resources Company | Billings, MT 59101 | Oil & Gas Operator | Dec 2019 |
| 3103 | North Pacific Oil And Gas, Inc | Houston, TX 77042 | Oil Operator | Mar 2013 |
| 3104 | North Plains Corp | Tulsa, OK 74137 | Oil & Gas Operator | Nov 2024 |
| 3105 | North Plains Oil | | Oil Operator | Jul 1990 |
| 3106 | Northern Gas Pro | | Gas Operator | Jun 1994 |
| 3107 | Northern Lights | | Oil & Gas Operator | Apr 1993 |
| 3108 | Northern Lights Oil Company, LLC | Andover, KS 67002 | Oil & Gas Operator | Nov 2024 |
| 3109 | Northern Natural Gas Prod | | Gas Operator | Oct 1989 |
| 3110 | Northern Pump Company | Denver, CO 80202-3130 | Oil & Gas Operator | Feb 2006 |
| 3111 | Northstar Investments, Inc. | Wichita, KS 67230 | Oil & Gas Operator | Nov 2024 |
| 3112 | Northwest Well Service, Inc. | Merino, CO 80741 | Oil Operator | Mar 2002 |
| 3113 | Norwood Oil | Greeley, CO 80634 | Oil Operator | Mar 1996 |
| 3114 | Nott, Gregory | Wichita, KS 67214 | Oil Operator | Nov 2024 |
| 3115 | Novy Oil & Gas, Inc. | Goddard, KS 67052 | Oil & Gas Operator | Jan 2025 |
| 3116 | Noxxe | Ottawa, KS 66067 | Oil & Gas Operator | Dec 2021 |
| 3117 | NPF Energy Corporation | Boise, ID 83708 | Oil & Gas Operator | Nov 2024 |
| 3118 | NRD - Rein Resources, A General Partnership | Union, KY 41091 | Oil Operator | Nov 2024 |
| 3119 | NTR Energy LLC | Caney, KS 67333 | Oil & Gas Operator | Apr 2020 |
| 3120 | Numac LLC | Cherryvale, KS 67335 | Oil Operator | Jun 2024 |
| 3121 | Nuss Oil Operations | | Oil & Gas Operator | Aug 1998 |
| 3122 | Nuss Sally | | Oil Operator | Mar 1982 |
| 3123 | Nuss, Fred J. | Hoisington, KS 67544 | Gas Operator | Nov 2024 |
| 3124 | Nuss, Kenneth J. | Russell, KS 67665 | Oil Operator | Aug 1997 |
| 3125 | O S & J Operatin | | Oil Operator | Nov 1984 |
| 3126 | O'Brien Energy Company | Shreveport, LA 71136 | Oil & Gas Operator | Sep 2019 |
| 3127 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | Mar 2025 |
| 3128 | O'Brien Resources LLC | Shreveport, LA 71136 | Oil Operator | Nov 2017 |
| 3129 | O'Connell, James P. | Vacaville, CA 95687 | Oil Operator | Nov 2009 |
| 3130 | O'Hare Energy Co | | Oil Operator | Dec 1983 |
| 3131 | Oak Ridge LLC | Wellsville, KS 66092 | Oil Operator | Dec 2019 |
| 3132 | Oaks Petroleum I | | Oil Operator | Jul 1987 |
| 3133 | Oakwood Resources, Inc. | Dallas, TX 75374 | Oil & Gas Operator | May 1998 |
| 3134 | Oasis Petroleum | | Gas Operator | Feb 1984 |
| 3135 | Oast, Thomas H. | Greenville, NC 27835 | Oil Operator | Nov 1985 |
| 3136 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 3137 | Ocean Energy Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Nov 2024 |
| 3138 | Ocfiw Oil Company, Inc. | Hartington, NE 68739 | Oil & Gas Operator | Dec 2009 |
| 3139 | Odyssey Petroleum, Inc. | Overland Park, KS 66282 | Oil & Gas Operator | Apr 2009 |
| 3140 | Ogh Oil Company | | Oil Operator | Sep 1995 |
| 3141 | Ohio Kentucky Oil Corporation | Lexington, KY 40503 | Oil & Gas Operator | Dec 2020 |
| 3142 | Oil & Gas Producers, Inc. | Topeka, KS 66604 | Oil Operator | Jun 2004 |
| 3143 | Oil & Gas Servic | | Oil Operator | Jun 1983 |
| 3144 | Oil Capital Corporation | Littleton, CO 80122 | Gas Operator | May 2009 |
| 3145 | Oil Company Of America, Inc. | Hays, KS 67601 | Oil Operator | Dec 2009 |
| 3146 | Oil Drillers & D | | Oil & Gas Operator | Feb 1992 |
| 3147 | Oil Equipment As | | Gas Operator | Jun 1989 |
| 3148 | Oil Field Manage | | Oil Operator | Jun 1991 |
| 3149 | Oil Gas Management, Inc. | Kansas City, MO 64106 | Oil Operator | Apr 2011 |
| 3150 | Oil Internationa | | Oil Operator | Jun 1986 |
| 3151 | Oil Lift, Incorporated | Metairie, LA 70002 | Oil & Gas Operator | Apr 2020 |
| 3152 | Oil Partners | Salina, KS 67401 | Oil Operator | Jun 2001 |
| 3153 | Oil Partners, LLC | Salina, KS 67401 | Oil Operator | Nov 2024 |
| 3154 | Oil Producers In | | Oil & Gas Operator | Dec 1996 |
| 3155 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 3156 | Oil Production S | | Oil Operator | Sep 1993 |
| 3157 | Oil Prop Company | | Oil & Gas Operator | Sep 1995 |
| 3158 | Oil Prop Investm | | Oil Operator | Dec 1995 |
| 3159 | Oil Properties Co., Inc. | Wichita, KS 67208 | Gas Operator | Dec 2009 |
| 3160 | Oil Property Man | | Oil & Gas Operator | Jun 1995 |
| 3161 | Oil Property Management, Inc. | Attica, KS 67009 | Oil & Gas Operator | Feb 2021 |
| 3162 | Oil Tech Producers Corporation | Moundridge, KS 67107 | Gas Operator | Nov 2024 |
| 3163 | Oil-Tech Prod Co | | Oil & Gas Operator | Oct 1992 |
| 3164 | Oilfield Search | | Oil Operator | Mar 1990 |
| 3165 | Oilfield Services, LLC | Winfield, KS 67156 | Oil Operator | Nov 2017 |
| 3166 | Oilfield Truck Service | | Oil Operator | Jun 2014 |
| 3167 | Oilwell Operator | | Gas Operator | Dec 1994 |
| 3168 | Oklahoma Energy & Exploration, Inc. | Tulsa, OK 74114 | Oil Operator | Jan 1996 |
| 3169 | Oklahoma Rig & Salvage, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 3170 | Okmar Oil Compan | | Oil & Gas Operator | Feb 1995 |
| 3171 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 3172 | Okt Resources, LLC | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |
| 3173 | Ol' Oily LLC | | Oil Operator | Nov 2024 |
| 3174 | Oleum Incorporat | | Gas Operator | Dec 1990 |
| 3175 | Olson D Producti | | Oil Operator | Jul 1994 |
| 3176 | Olson-Anderson Lease | | Oil Operator | Mar 2018 |
| 3177 | Olympic Oil, Inc. | Hutchinson, KS 67502 | Oil & Gas Operator | May 2024 |
| 3178 | Olympic Petroleu | | Oil & Gas Operator | Jul 1993 |
| 3179 | Omega Enterprise | | Oil Operator | Sep 1990 |
| 3180 | One Source Financial Services Inc. | McAllen, TX 78501 | Gas Operator | Dec 2019 |
| 3181 | Oneok Bushton Proces | | Gas Operator | Mar 2007 |
| 3182 | Oneok Energy Service | | Gas Operator | Dec 2008 |
| 3183 | Oneok Exploratio | | Oil & Gas Operator | Mar 1995 |
| 3184 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 3185 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 3186 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 3187 | Onnen, Gerhard E. | Yates Center, KS 66783 | Oil Operator | Feb 2002 |
| 3188 | Onshore, L.L.C. | Wichita, KS 67205 | Oil & Gas Operator | Dec 2009 |
| 3189 | Onyxx Oil Corpor | | Oil Operator | Jul 1992 |
| 3190 | Oolite Energy Corp | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2022 |
| 3191 | Opco LLC | Chase, KS 67524 | Oil Operator | Dec 2019 |
| 3192 | Opdycke Lease Partners, A General Partnership | Russell, KS 67665 | Oil Operator | Nov 2024 |
| 3193 | Opef Partnership, A General Partnership | Overland Park, KS 66221 | Oil Operator | Dec 2011 |
| 3194 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2025 |
| 3195 | Oryx Energy Comp | | Oil & Gas Operator | Apr 1991 |
| 3196 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 3197 | Osage Energy LLC | Colony, KS 66015 | Oil Operator | Nov 2023 |
| 3198 | Osage Resources, LLC | Wichita, KS 67202 | Oil & Gas Operator | Aug 2024 |
| 3199 | Osborn Energy, L.L.C. | Bucyrus, KS 66013 | Oil & Gas Operator | Jul 2017 |
| 3200 | Osborn Heirs Com | | Oil & Gas Operator | May 1995 |