| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | H & C Oil Operat | Oil & Gas Operator | Dec 1996 | |
| 2 | H & C Oil Operating Inc. | Plainville, KS 67663 | Oil & Gas Operator | Jun 2025 |
| 3 | H & M Petroleum Corporation | Lincoln, NE 68516 | Oil & Gas Operator | Jun 2025 |
| 4 | H-30 Incorporate | Oil & Gas Operator | Nov 1990 | |
| 5 | H3 Oil & Gas | Oil & Gas Operator | Jun 2025 | |
| 6 | Hansen Dane G TR | Oil Operator | Feb 1995 | |
| 7 | Helmerich & Payn | Oil & Gas Operator | Aug 1995 | |
| 8 | Heritage Oil L.L.C. | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 9 | Herman L. Loeb LLC | Lawrenceville, IL 62439 | Oil & Gas Operator | Jun 2025 |
| 10 | Hess Oil Company | McPherson, KS 67460 | Oil & Gas Operator | Jun 2025 |
| 11 | HG Oil Holdings, LLC | Hoisington, KS 67544 | Oil & Gas Operator | Jun 2025 |
| 12 | High Plains Oil | Oil Operator | Jun 1989 | |
| 13 | Hoffman Petroleu | Oil Operator | Sep 1989 | |
| 14 | Hyde-Marrs, Inc. | Wichita, KS 67202 | Oil Operator | Aug 1997 |