# Relationship history for MSHA mine 4500081

Current hierarchy: **Peter Kiewit Sons' Inc → Gilbert Western Corp → Fisher Quarry**

- 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:** Bohemia Inc → Fisher Quarry; 1950-01-01 to 1984-09-10; source msha-controller-operator-history
- **controller_controls_mine:** Dick  Tinney → Fisher Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dick  Tinney → Bohemia Inc; 1950-01-01 to 1984-09-10; source msha-controller-operator-history
- **controller_controls_mine:** Peter Kiewit Sons' Inc → Fisher Quarry; 1982-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gilbert Western Corp → Fisher Quarry; 1984-09-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter Kiewit Sons' Inc → Gilbert Western Corp; 1984-09-11 to current/open; source msha-controller-operator-history