# Relationship history for MSHA mine 4604696

Current hierarchy: **Crabtree Lloyd → J B C Coal Company → 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:** Sherman Jerry → No 1 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M T R Mining Corp → No 1 Mine; 1975-07-01 to 1976-03-04; source msha-controller-operator-history
- **controller_controls_operator:** Sherman Jerry → M T R Mining Corp; 1975-07-01 to 1976-03-04; source msha-controller-operator-history
- **operator_operates_mine:** J B C Coal Company → No 1 Mine; 1976-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crabtree Lloyd → No 1 Mine; 1976-03-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crabtree Lloyd → J B C Coal Company; 1976-03-05 to current/open; source msha-controller-operator-history