# Relationship history for MSHA mine 4405995

Current hierarchy: **Amvest Corporation → Natural Fuel Company → No 1 Strip**

- 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:** Natural Fuel Company → No 1 Strip; 1984-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Amvest Corporation → No 1 Strip; 1984-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Natural Fuel Company; 1984-05-01 to current/open; source msha-controller-operator-history