# Relationship history for MSHA mine 1509647

Current hierarchy: **Martin Russell → T R B & B Coal Company Inc → 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

- **operator_operates_mine:** Mountain Empire Coal Company → No 1 Mine; 1976-04-02 to 1977-08-01; source msha-controller-operator-history
- **controller_controls_mine:** Crase Tilden Jr → No 1 Mine; 1976-04-02 to 1977-08-01; source msha-controller-operator-history
- **controller_controls_operator:** Crase Tilden Jr → Mountain Empire Coal Company; 1976-04-02 to 1977-08-01; source msha-controller-operator-history
- **operator_operates_mine:** T R B & B Coal Company Inc → No 1 Mine; 1977-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Russell → No 1 Mine; 1977-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Russell → T R B & B Coal Company Inc; 1977-08-02 to current/open; source msha-controller-operator-history