# Relationship history for MSHA mine 1512388

Current hierarchy: **Walters Luke → Erby Coal Company → Earby 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

- **operator_operates_mine:** Erby Coal Company → Earby No 1; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Walters Luke → Earby No 1; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walters Luke → Erby Coal Company; 1980-04-01 to current/open; source msha-controller-operator-history