# Relationship history for MSHA mine 4105295

Current hierarchy: **CRH PLC → Texas Materials Group Inc. → Portable Plant 01**

- 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:** Ashland Inc → Portable Plant 01; 1999-07-01 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Portable Plant 01; 2006-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Portable Plant 01; 2014-05-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Oldcastle Materials Texas Inc. → Portable Plant 01; 2017-09-07 to 2020-02-24; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Oldcastle Materials Texas Inc.; 2017-09-07 to 2020-02-24; source msha-controller-operator-history
- **operator_operates_mine:** Texas Materials Group Inc. → Portable Plant 01; 2020-02-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → Texas Materials Group Inc.; 2020-02-25 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Texas Materials Group Inc.; 2020-02-25 to current/open; source msha-controller-operator-history