# Relationship history for MSHA mine 0201737

Current hierarchy: **Howard David → Tombstone Silver Mines Inc → State Of Maine 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** State Of Maine Mining Company → State Of Maine Mine; 1950-01-01 to 1984-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Escapule Charles B & Louis W → State Of Maine Mine; 1950-01-01 to 1984-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Escapule Charles B & Louis W → State Of Maine Mining Company; 1950-01-01 to 1984-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Tombstone Silver Mines Inc → State Of Maine Mine; 1984-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Howard David → State Of Maine Mine; 1984-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Howard David → Tombstone Silver Mines Inc; 1984-11-14 to current/open; source msha-controller-operator-history