# Relationship history for MSHA mine 1515588

Current hierarchy: **Noranda Group → Norcoal Kentucky Inc → No 3**

- 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:** Noranda Group → No 3; 1984-10-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Norcoal Kentucky Inc → No 3; 1986-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Noranda Group → Norcoal Kentucky Inc; 1986-04-01 to current/open; source msha-controller-operator-history