# Relationship history for MSHA mine 1401646

Current hierarchy: **CRH PLC → Holliday Sand & Gravel Company, Inc. → HSS Q Portable Plant 1**

- 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:** Ash Grove Cement Company → HSS Q Portable Plant 1; 1950-01-01 to 2018-06-20; source msha-controller-operator-history
- **operator_operates_mine:** Ash Grove Aggregates Inc → HSS Q Portable Plant 1; 2005-09-14 to 2021-03-30; source msha-controller-operator-history
- **controller_controls_operator:** Ash Grove Cement Company → Ash Grove Aggregates Inc; 2005-09-14 to 2018-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Ash Grove Cement Company → HSS Q Portable Plant 1; 2008-08-01 to 2018-06-20; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → HSS Q Portable Plant 1; 2018-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Ash Grove Aggregates Inc; 2018-06-21 to 2021-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Holliday Sand & Gravel Company, Inc. → HSS Q Portable Plant 1; 2021-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ash Grove Cement Company → Holliday Sand & Gravel Company, Inc.; 2021-03-31 to 2018-06-20; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Holliday Sand & Gravel Company, Inc.; 2021-03-31 to current/open; source msha-controller-operator-history