| 4001 | Sieg Energy, Inc. | Ottawa, KS 66067 | Oil Operator | May 2025 |
| 4002 | Siegfried R H In | | Oil Operator | Apr 1985 |
| 4003 | Siemsen Operating, LLC | Holyrood, KS 67450 | Oil Operator | Jun 2025 |
| 4004 | Sierra Drilling | | Oil Operator | Sep 1988 |
| 4005 | Sierra Madre LLC | Greensburg, KS 67054 | Oil & Gas Operator | May 2015 |
| 4006 | Sierra Petroleum | | Oil & Gas Operator | Sep 1986 |
| 4007 | Silhan, Terry | Marion, KS 66861 | Oil & Gas Operator | Dec 2009 |
| 4008 | Silver Creek Oil | Merkel, TX 79536 | Oil & Gas Operator | Aug 2003 |
| 4009 | Silver Creek Oil & Gas, Inc. | Wichita, KS 67203 | Oil Operator | Dec 1997 |
| 4010 | Simasko Producti | | Oil Operator | Dec 1986 |
| 4011 | Simco Petroleum | Cheyenne, WY 82003 | Oil & Gas Operator | Oct 2009 |
| 4012 | Simminger, Robert John Jr | | Oil Operator | May 2025 |
| 4013 | Simmons Oil Corp | | Oil Operator | Jan 1989 |
| 4014 | Simmons Robert Z | | Oil Operator | Dec 1990 |
| 4015 | Single Barrel Oil And Gas LLC | Granbury, TX 76048 | Oil & Gas Operator | Dec 2025 |
| 4016 | Sirius Energy Corp. | Abilene, TX 79606 | Oil Operator | Dec 2009 |
| 4017 | Siroky Oil Management | Pratt, KS 67124 | Oil & Gas Operator | Jun 2025 |
| 4018 | Six-D Exploration, LLC | Hutchinson, KS 67502 | Oil Operator | Apr 2025 |
| 4019 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 4020 | SKKM Oil Company | | Oil Operator | Dec 1992 |
| 4021 | Sky Oil, L.L.C. | St. Paul, KS 66771 | Oil Operator | Dec 2004 |
| 4022 | Slawson Donald C | Wichita, KS 67202 | Oil & Gas Operator | Apr 2025 |
| 4023 | Slawson Explorat | | Oil & Gas Operator | Dec 1996 |
| 4024 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 4025 | SLMW Energy Comp | | Oil Operator | Jan 1989 |
| 4026 | Slo Oil, LLC | El Dorado, KS 67042 | Oil Operator | Nov 2024 |
| 4027 | Sloan Operations | | Oil Operator | Mar 2025 |
| 4028 | SM Oil & Gas Inc | Skiatook, OK 74070 | Oil & Gas Operator | Aug 2025 |
| 4029 | SMG Resources LLC | | Oil & Gas Operator | Jun 2025 |
| 4030 | Smith Cattle Inc | | Gas Operator | Dec 1994 |
| 4031 | Smith Oil & Gas LLC | Livermore, CO 80536 | Gas Operator | Jun 2025 |
| 4032 | Smith Oil Co. | Smackover, AR 71762 | Oil Operator | Jan 2025 |
| 4033 | Smith Oil Compan | | Oil Operator | Sep 1994 |
| 4034 | Smith Oil Operations | | Oil & Gas Operator | Jun 2025 |
| 4035 | Smith Ranch Company | Sharon Springs, KS 67758 | Gas Operator | May 2002 |
| 4036 | Smith Richard F | | Oil Operator | Jun 1995 |
| 4037 | Smith Todd W Oil | | Oil Operator | Jan 1994 |
| 4038 | Smith, Darrin R | Wilson, KS 67490 | Oil Operator | May 2025 |
| 4039 | Smith, David | Wichita Falls, TX 76310 | Oil Operator | Dec 2025 |
| 4040 | Smith, Edward J. | Clifton, NJ 07013 | Oil & Gas Operator | Dec 1995 |
| 4041 | Smith, Gordon R. | Madison, KS 66860 | Oil Operator | Nov 1998 |
| 4042 | Smith, Loren L. | Oswego, KS 67356 | Oil & Gas Operator | Sep 2009 |
| 4043 | Smith, Wanda | Syracuse, KS 67878 | Oil & Gas Operator | Sep 2014 |
| 4044 | Smitherman, Leon C., Jr. | Andover, KS 67002 | Oil Operator | Dec 2019 |
| 4045 | Smokey Valley Resources | Lyons, KS 67554 | Oil Operator | Jun 1998 |
| 4046 | Smokey Valley Resources, Inc. | Geneseo, KS 67444 | Oil Operator | Nov 2008 |
| 4047 | Smoky Valley Res | | Oil & Gas Operator | Dec 1995 |
| 4048 | Snedco, Inc. | Chickasha, OK 73023 | Oil Operator | May 2025 |
| 4049 | Snow Oil Company | Nocona, TX 76255 | Oil Operator | Dec 2025 |
| 4050 | SNR Kansas Operating, LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Dec 2019 |
| 4051 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Dec 2025 |
| 4052 | Snyder K E Compa | | Oil Operator | Jul 1987 |
| 4053 | Snyder Partners, General Partnership | Cody, WY 82414 | Oil & Gas Operator | Jul 2019 |
| 4054 | Snyder, Jim Estate (Deceased) | Hamilton, KS 66853 | Oil Operator | Dec 2009 |
| 4055 | Snyder, K. Lance | Hamilton, KS 66853 | Oil Operator | Nov 2004 |
| 4056 | So & Jo, LLC | Kansas City, MO 64158 | Oil Operator | Dec 2021 |
| 4057 | So-I , A General Partnership | Kansas City, MO 64106 | Oil & Gas Operator | Jun 2025 |
| 4058 | Sokan Operating, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Jun 2025 |
| 4059 | Soles Larry - Fe | | Oil Operator | Nov 1986 |
| 4060 | Somerset Energy | | Oil Operator | Feb 1986 |
| 4061 | Somerset Energy, Inc. | Louisburg, KS 66053 | Oil Operator | Dec 2023 |
| 4062 | Sommer Oil LLC | Richmond, KS 66080 | Oil Operator | Jun 2025 |
| 4063 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 4064 | Sonoma Resources LLC | Andover, KS 67002 | Oil & Gas Operator | Jun 2025 |
| 4065 | Sorensen, Kim A. | Abbyville, KS 67510 | Oil Operator | Mar 2025 |
| 4066 | Sotta, Donald E. | McCune, KS 66753 | Oil Operator | Dec 2024 |
| 4067 | Soule, Gilbert A. | Madison, KS 66860 | Oil Operator | Jan 2002 |
| 4068 | Soule, Richard A. | Eureka, KS 67045 | Oil Operator | Sep 2019 |
| 4069 | Source Energy Midcon LLC | Highlands Ranch, CO 80129 | Oil Operator | Jul 2015 |
| 4070 | Source Petroleum | Wichita, KS 67202 | Oil & Gas Operator | Oct 1993 |
| 4071 | South Bay Oil Corporation | Wichita, KS 67202 | Oil Operator | Dec 2019 |
| 4072 | South Central Oil And Gas | | Oil & Gas Operator | Feb 2014 |
| 4073 | South Forty Inc (The) | Laverne, OK 73848 | Oil & Gas Operator | Mar 2015 |
| 4074 | South Of Briles | | Oil Operator | Aug 1989 |
| 4075 | South Ranch Oil | | Gas Operator | Dec 1990 |
| 4076 | Southern Gas Inc | | Gas Operator | Jan 1987 |
| 4077 | Southern Hills Gas Co. | | Oil Operator | May 2025 |
| 4078 | Southern Star Central Gas Pipeline Inc | Owensboro, KY 42301 | Oil & Gas Operator | May 2025 |
| 4079 | Southern States | | Oil & Gas Operator | Jul 1988 |
| 4080 | Southland Royalt | | Oil & Gas Operator | Nov 1993 |
| 4081 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 4082 | Southwest Gas St | | Oil & Gas Operator | Dec 1981 |
| 4083 | Southwest Gas Storage Company | | Gas Operator | Jun 2025 |
| 4084 | Southwest Operating Company | Overland Park, KS 66212 | Oil & Gas Operator | Mar 2012 |
| 4085 | Southwind Consulting | Pratt, KS 67124 | Oil Operator | Oct 1997 |
| 4086 | Southwind Exploration, LLC | Venice, FL 34293 | Oil & Gas Operator | Sep 2003 |
| 4087 | Southwind Petroleum Corp. | Wichita, KS 67203 | Oil & Gas Operator | Jun 2022 |
| 4088 | Sovereign Operating Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2016 |
| 4089 | Sowle Exploratio | | Oil Operator | Aug 1986 |
| 4090 | Sowle Explorations | | Oil Operator | Dec 2002 |
| 4091 | Spalsbury, Arthur L | Hays, KS 67601 | Oil Operator | Aug 2001 |
| 4092 | Specht Farms | Piqua, KS 66761 | Oil Operator | Nov 2009 |
| 4093 | Specht Oil | Iola, KS 66749 | Oil Operator | Mar 1998 |
| 4094 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Dec 2025 |
| 4095 | Speedy Well Service | | Oil & Gas Operator | Jun 2025 |
| 4096 | Spess Oil Company, A General Partnership | Cleveland, OK 74020 | Oil & Gas Operator | Jun 2025 |
| 4097 | Spikes Gas & Oil | | Gas Operator | Mar 1994 |
| 4098 | Spikes, Gary E. | Garden City, KS 67846 | Gas Operator | Mar 2013 |
| 4099 | Spindletop Oil & | | Oil Operator | Jun 1993 |
| 4100 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Dec 2025 |