# Relationship history for MSHA mine 1508018

Current hierarchy: **Shepherd Henry → H H & R Coal Company → No 1 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

- **operator_operates_mine:** H H & R Coal Company → No 1 Mine; 1974-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shepherd Henry Et Al → No 1 Mine; 1974-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shepherd Henry Et Al → H H & R Coal Company; 1974-12-01 to current/open; source msha-controller-operator-history