# Relationship history for MSHA mine 1502758

Current hierarchy: **Isaac Basil → Isaac Coal Company Inc → No 4 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:** Christopher Coal Company → No 4 Mine; 1950-01-01 to 1979-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Mc Garey Lloyd → No 4 Mine; 1950-01-01 to 1979-07-30; source msha-controller-operator-history
- **controller_controls_operator:** Mc Garey Lloyd → Christopher Coal Company; 1950-01-01 to 1979-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Isaac Basil → No 4 Mine; 1978-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Isaac Coal Company Inc → No 4 Mine; 1979-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Isaac Basil → Isaac Coal Company Inc; 1979-07-31 to current/open; source msha-controller-operator-history