# Relationship history for MSHA mine 3500727

Current hierarchy: **George Harold Fitzhugh; John David Baldwin → Production Crushers → Production Crushers**

- 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:** Production Crushers → Production Crushers; 1978-03-09 to 1986-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Acco Contractors → Production Crushers; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Acco Contractors → Production Crushers; 1978-03-09 to 1986-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Dave  Baldwin et al → Production Crushers; 1979-01-01 to 2023-05-14; source msha-controller-operator-history
- **operator_operates_mine:** Production Crushers → Production Crushers; 1986-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Baldwin et al → Production Crushers; 1986-05-07 to 2023-05-14; source msha-controller-operator-history
- **controller_controls_operator:** Jess  Fitzhugh et al → Production Crushers; 1986-05-07 to 2023-05-14; source msha-controller-operator-history
- **controller_controls_mine:** John David Baldwin et al → Production Crushers; 2023-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John David Baldwin et al → Production Crushers; 2023-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George Harold Fitzhugh et al → Production Crushers; 2023-05-15 to current/open; source msha-controller-operator-history