# Relationship history for MSHA mine 1001976

Current hierarchy: **CRH PLC → Idaho Materials & Construction → Greenleaf**

- 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:** U S Aggregate Inc → Greenleaf; 1986-06-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Monroc Inc → Greenleaf; 2000-01-01 to 2002-02-05; source msha-controller-operator-history
- **controller_controls_operator:** U S Aggregate Inc → Monroc Inc; 2000-01-01 to 2002-02-05; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Greenleaf; 2000-03-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Idaho Materials & Construction → Greenleaf; 2002-02-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Idaho Materials & Construction; 2002-02-06 to current/open; source msha-controller-operator-history