# Relationship history for MSHA mine 1001912

Current hierarchy: **CRH PLC → Interstate Concrete and Asphalt Company → Wyoming Facility**

- 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:** CRH PLC → Wyoming Facility; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Wyoming Facility; 1987-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Wyoming Facility; 1988-11-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Acme Materials & Construction Company → Wyoming Facility; 1995-04-01 to 2000-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Acme Materials & Construction Company; 1995-04-01 to 2000-06-29; source msha-controller-operator-history
- **operator_operates_mine:** Central Pre-Mix Concrete Company → Wyoming Facility; 2000-06-30 to 2004-06-30; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Central Pre-Mix Concrete Company; 2000-06-30 to 2004-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Interstate Concrete and Asphalt Company → Wyoming Facility; 2004-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Interstate Concrete and Asphalt Company; 2004-07-01 to current/open; source msha-controller-operator-history