# Relationship history for MSHA mine 4503211

Current hierarchy: **Koepke Marie → Silver Bell Mining → Silver Bell**

- 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:** Koepke Marie → Silver Bell; 1982-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Silver Bell Mining → Silver Bell; 1989-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Koepke Marie → Silver Bell Mining; 1989-10-01 to current/open; source msha-controller-operator-history