# Relationship history for MSHA mine 1508468

Current hierarchy: **Asher Logan & Oscar Kilburn → Campbell 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

- **operator_operates_mine:** Campbell Coal Company → No 1 Mine; 1975-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Asher Logan & Oscar Kilburn → No 1 Mine; 1975-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Asher Logan & Oscar Kilburn → Campbell Coal Company; 1975-05-01 to current/open; source msha-controller-operator-history