| 1 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Jun 2025 |
| 2 | Kanokla Oil & Gas Corporation | Wellington, KS 67152-0444 | Oil & Gas Operator | Feb 2025 |
| 3 | Kato Operating Company | Bristow, OK 74010 | Oil & Gas Operator | Mar 2015 |
| 4 | KC Resources Inc | Snowmass VLG., CO 81615 | Oil & Gas Operator | Feb 2025 |
| 5 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 6 | Keith F. Walker Oil & Gas Co., LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2025 |
| 7 | Kelloil Inc | Fort Worth, TX 76116-5600 | Oil & Gas Operator | Mar 2015 |
| 8 | Kennedy & Mitchell, Inc. | Houston, TX 77084 | Oil & Gas Operator | Aug 2013 |
| 9 | Kenneth W. Cory, LTD. | Bellaire, TX 77401 | Oil & Gas Operator | Mar 2025 |
| 10 | Kerr McGee Rocky MTN Corp | Denver, CO 80202-5736 | Oil & Gas Operator | Mar 2015 |
| 11 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 12 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 13 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Jun 2025 |
| 14 | Key Production Company, Inc. | Longview, TX 75606 | Oil & Gas Operator | Mar 2025 |
| 15 | Kickapoo Oil Co | Baton Rouge, LA 70815 | Gas Operator | Feb 1994 |
| 16 | Kimbark Oil & Gas Company | Denver, CO 80203 | Oil & Gas Operator | May 2007 |
| 17 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Jun 2025 |
| 18 | Kleen Oilfield Services Co | Velma, OK 73491-0178 | Oil & Gas Operator | Mar 2025 |
| 19 | KN Production Co. | Lakewood, CO 80228 | Oil & Gas Operator | Jun 2003 |
| 20 | KNG Producers | Dumas, TX 79029 | Oil & Gas Operator | Oct 2009 |
| 21 | Koch Oil Company | | Oil & Gas Operator | May 2017 |
| 22 | KP Exploration, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1997 |