# Relationship history for MSHA mine 1509523

Current hierarchy: **Elswick Warren → Jimmies Creek Coal Company → No 20-C 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:** Wellman Willis → No 20-C Mine; 1974-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Jimmies Creek Coal Company → No 20-C Mine; 1976-03-04 to 1976-08-30; source msha-controller-operator-history
- **controller_controls_operator:** Wellman Willis → Jimmies Creek Coal Company; 1976-03-04 to 1976-08-30; source msha-controller-operator-history
- **operator_operates_mine:** Jimmies Creek Coal Company → No 20-C Mine; 1976-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Elswick Warren → No 20-C Mine; 1976-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elswick Warren → Jimmies Creek Coal Company; 1976-08-31 to current/open; source msha-controller-operator-history