# Relationship history for MSHA mine 3304027

Current hierarchy: **Merckle Manford → Kymcoal Inc → Kymcoal #2**

- 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:** Merckle Manford → Kymcoal #2; 1984-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kymcoal Inc → Kymcoal #2; 1985-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Merckle Manford → Kymcoal Inc; 1985-08-01 to current/open; source msha-controller-operator-history