# Relationship history for MSHA mine 4405801

Current hierarchy: **Keen Boyd → K & H Coal Company Inc → Mine No 1**

- 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

- **operator_operates_mine:** C & B Coal Company → Mine No 1; 1981-11-01 to 1984-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Frank Charles → Mine No 1; 1981-11-01 to 1984-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Frank Charles → C & B Coal Company; 1981-11-01 to 1984-08-22; source msha-controller-operator-history
- **operator_operates_mine:** K & H Coal Company Inc → Mine No 1; 1984-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keen Boyd → Mine No 1; 1984-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keen Boyd → K & H Coal Company Inc; 1984-08-23 to current/open; source msha-controller-operator-history