# Relationship history for MSHA mine 4002029

Current hierarchy: **Campbell Jerry → J & U 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** J & U Coal Company → No 1 Mine; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Campbell Jerry → No 1 Mine; 1976-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Campbell Jerry → J & U Coal Company; 1976-03-01 to current/open; source msha-controller-operator-history