# Relationship history for MSHA mine 1502749

Current hierarchy: **Tyler Marvin & Charles Stofer → T & S Coal Company → No 21 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** B & S Coal Company Inc → No 21 Mine; 1950-01-01 to 1977-02-09; source msha-controller-operator-history
- **controller_controls_mine:** Banks Hubert--Willie & Luther Hurley → No 21 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Banks Hubert--Willie & Luther Hurley → B & S Coal Company Inc; 1950-01-01 to 1977-02-09; source msha-controller-operator-history
- **operator_operates_mine:** T & S Coal Company → No 21 Mine; 1977-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tyler Marvin & Charles Stofer → No 21 Mine; 1977-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tyler Marvin & Charles Stofer → T & S Coal Company; 1977-02-10 to current/open; source msha-controller-operator-history