# Relationship history for MSHA mine 1516409

Current hierarchy: **Williamson Charles O → St Johns Mining Company → 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

- **controller_controls_mine:** Williamson Charles O → No 1; 1988-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Down-Under Mining Company → No 1; 1988-06-01 to 1989-01-11; source msha-controller-operator-history
- **controller_controls_mine:** Hurst Ray → No 1; 1988-06-01 to 1989-01-11; source msha-controller-operator-history
- **controller_controls_operator:** Hurst Ray → Down-Under Mining Company; 1988-06-01 to 1989-01-11; source msha-controller-operator-history
- **operator_operates_mine:** St Johns Mining Company → No 1; 1989-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williamson Charles O → St Johns Mining Company; 1989-01-12 to current/open; source msha-controller-operator-history