# Relationship history for MSHA mine 3609697

Current hierarchy: **Blaine E  Forbes → Grove City Materials → Uschak**

- 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:** Grove City Materials → Uschak; 2010-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blaine E  Forbes et al → Uschak; 2010-06-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blaine E  Forbes et al → Grove City Materials; 2010-06-14 to current/open; source msha-controller-operator-history