# Relationship history for MSHA mine 3503854

Current hierarchy: **Mike  Sarin → Big River Excavating → Portable Crusher**

- 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:** Mike  Sarin et al → Portable Crusher; 2014-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big River Excavating → Portable Crusher; 2016-09-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mike  Sarin et al → Big River Excavating; 2016-09-26 to current/open; source msha-controller-operator-history