# Relationship history for MSHA mine 2103722

Current hierarchy: **Katherine L  Novak; Luke E  Helmin → Helmin Construction Inc → Hewitt-Robins Screener**

- 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:** William E  Helmin → Hewitt-Robins Screener; 2007-07-16 to 2012-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Helmin Construction Inc → Hewitt-Robins Screener; 2010-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William E  Helmin → Helmin Construction Inc; 2010-09-22 to 2012-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Katherine L  Novak et al → Hewitt-Robins Screener; 2012-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Katherine L  Novak et al → Helmin Construction Inc; 2012-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Luke E  Helmin et al → Helmin Construction Inc; 2012-10-12 to current/open; source msha-controller-operator-history