# Relationship history for MSHA mine 2003621

Current hierarchy: **John S  Yerington II → Michiana Aggregate → Findlay**

- 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:** John S  Yerington II → Findlay; 1994-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Michiana Aggregate → Findlay; 2021-09-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John S  Yerington II → Michiana Aggregate; 2021-09-16 to current/open; source msha-controller-operator-history