# Relationship history for MSHA mine 4606321

Current hierarchy: **Huff Charles S & William C Tonkery → Huff Coal Company → Huff Coal Co Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Huff Coal Company → Huff Coal Co Mine; 1981-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Huff Charles S & William C Tonkery → Huff Coal Co Mine; 1981-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Huff Charles S & William C Tonkery → Huff Coal Company; 1981-04-01 to current/open; source msha-controller-operator-history