# Relationship history for MSHA mine 4000609

Current hierarchy: **Thomas Virgil C → T T & W Coal Company → Sunbright No 1 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

- **controller_controls_mine:** Thomas Virgil C Et Al → Sunbright No 1 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C & C Products → Sunbright No 1 Mine; 1950-01-01 to 1974-07-31; source msha-controller-operator-history
- **controller_controls_mine:** C & C Products → Sunbright No 1 Mine; 1950-01-01 to 1974-07-31; source msha-controller-operator-history
- **controller_controls_operator:** C & C Products → C & C Products; 1950-01-01 to 1974-07-31; source msha-controller-operator-history
- **operator_operates_mine:** T T & W Coal Company → Sunbright No 1 Mine; 1974-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas Virgil C Et Al → T T & W Coal Company; 1974-08-01 to current/open; source msha-controller-operator-history