# Relationship history for MSHA mine 1700936

Current hierarchy: **Kevin L  Vining → E.L. Vining & Son, Inc → Powerscreen #212**

- 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:** Kevin L  Vining → Powerscreen #212; 2004-04-20 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** E.L. Vining & Son, Inc → Powerscreen #212; 2014-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kevin L  Vining → E.L. Vining & Son, Inc; 2014-05-27 to current/open; source msha-controller-operator-history