# Relationship history for MSHA mine 3901550

Current hierarchy: **Colas S A → Simon Contractors → Portable Crusher and Screen**

- 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:** Colas S A → Portable Crusher and Screen; 1995-01-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Portable Crusher and Screen; 1998-10-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hills Materials Company → Portable Crusher and Screen; 2010-03-15 to 2015-03-29; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Hills Materials Company; 2010-03-15 to 2015-03-29; source msha-controller-operator-history
- **operator_operates_mine:** Simon Contractors → Portable Crusher and Screen; 2015-03-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → Simon Contractors; 2015-03-30 to current/open; source msha-controller-operator-history