# Relationship history for MSHA mine 4503721

Current hierarchy: **CRH PLC → American Rock Products → ARP Portable 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

- **controller_controls_mine:** Steve  Sali  et al → ARP Portable Wash Plant; 1978-08-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → ARP Portable Wash Plant; 1987-09-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Columbia Ready-Mix, Inc. → ARP Portable Wash Plant; 2013-12-04 to 2017-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Sali  et al → Columbia Ready-Mix, Inc.; 2013-12-04 to 2017-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence  Sali  et al → Columbia Ready-Mix, Inc.; 2013-12-04 to 2017-02-12; source msha-controller-operator-history
- **operator_operates_mine:** American Rock Products → ARP Portable Wash Plant; 2017-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → American Rock Products; 2017-02-13 to current/open; source msha-controller-operator-history