# Relationship history for MSHA mine 1514158

Current hierarchy: **Mc Kee Cliff & Gurney Neace → Hallmark Coal Company Inc → No 1 Prep Plant**

- 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:** Mc Kee Cliff & Gurney Neace → No 1 Prep Plant; 1983-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hallmark Coal Company Inc → No 1 Prep Plant; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Kee Cliff & Gurney Neace → Hallmark Coal Company Inc; 1983-08-01 to current/open; source msha-controller-operator-history