# Relationship history for MSHA mine 4405837

Current hierarchy: **Ashby Roger L → High Knob Mining Company → No 1 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Ward Jack J → No 1 Mine; 1981-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** High Knob Mining Company → No 1 Mine; 1982-02-01 to 1982-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Ward Jack J → High Knob Mining Company; 1982-02-01 to 1982-03-31; source msha-controller-operator-history
- **operator_operates_mine:** High Knob Mining Company → No 1 Mine; 1982-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ashby Roger L → No 1 Mine; 1982-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashby Roger L → High Knob Mining Company; 1982-04-01 to current/open; source msha-controller-operator-history