# Relationship history for MSHA mine 4201089

Current hierarchy: **CRH PLC → Western Rock Products → Centerfield Wash Plant**

- 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

- **operator_operates_mine:** Cox Rock Products, Inc. → Centerfield Wash Plant; 1950-01-01 to 2002-06-26; source msha-controller-operator-history
- **controller_controls_mine:** U S Aggregate Inc → Centerfield Wash Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** U S Aggregate Inc → Cox Rock Products, Inc.; 1950-01-01 to 2002-06-26; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Centerfield Wash Plant; 2002-05-29 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Rock Products → Centerfield Wash Plant; 2002-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Western Rock Products; 2002-06-27 to current/open; source msha-controller-operator-history