# Relationship history for MSHA mine 1507992

Current hierarchy: **Miniard Henry → Henry Miniard Coal Company → No 1 Mines**

- 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:** Henry Miniard Coal Company → No 1 Mines; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Miniard Henry → No 1 Mines; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Miniard Henry → Henry Miniard Coal Company; 1975-01-01 to current/open; source msha-controller-operator-history