# Relationship history for MSHA mine 3501640

Current hierarchy: **Hulsey Gregory S → G S Hulsey Crushing Inc → Miller Ridge Pit And Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Acco Contractors Inc → Miller Ridge Pit And Plant; 1950-01-01 to 1980-03-10; source msha-controller-operator-history
- **controller_controls_mine:** Acco Contractors → Miller Ridge Pit And Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Acco Contractors → Acco Contractors Inc; 1950-01-01 to 1980-03-10; source msha-controller-operator-history
- **controller_controls_mine:** Hulsey Gregory S → Miller Ridge Pit And Plant; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** G S Hulsey Crushing Inc → Miller Ridge Pit And Plant; 1980-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hulsey Gregory S → G S Hulsey Crushing Inc; 1980-03-11 to current/open; source msha-controller-operator-history