# Relationship history for MSHA mine 0405684

Current hierarchy: **Scott  Farley; Kurt  Kernen → Kernen Construction → Extec**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Scott  Farley et al → Extec; 1998-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kernen Construction → Extec; 2006-04-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Scott  Farley et al → Kernen Construction; 2006-04-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kurt  Kernen et al → Kernen Construction; 2006-04-17 to current/open; source msha-controller-operator-history