# Relationship history for MSHA mine 1514790

Current hierarchy: **Keel Hearl L → J & H Construction → No 1 Surface**

- 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:** J & H Construction → No 1 Surface; 1984-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keel Hearl L → No 1 Surface; 1984-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keel Hearl L → J & H Construction; 1984-08-01 to current/open; source msha-controller-operator-history