# Relationship history for MSHA mine 3303987

Current hierarchy: **Lewis William T → Lisbon Coal Crushers Inc → Leetonia Mine**

- 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:** Lisbon Coal Crushers Inc → Leetonia Mine; 1984-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lewis William T → Leetonia Mine; 1984-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lewis William T → Lisbon Coal Crushers Inc; 1984-10-01 to current/open; source msha-controller-operator-history