# Relationship history for MSHA mine 1513809

Current hierarchy: **Ledford Billy J → H R N Coal Company Inc → No 3 Surface 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:** Ledford Billy J → No 3 Surface Mine; 1976-10-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H R N Coal Company Inc → No 3 Surface Mine; 1982-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ledford Billy J → H R N Coal Company Inc; 1982-11-01 to current/open; source msha-controller-operator-history