# Relationship history for MSHA mine 3609418

Current hierarchy: **CRH PLC → Pennsy Supply Inc. → Hummelstown Fine Grind 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:** CRH PLC → Hummelstown Fine Grind Plant; 1993-07-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Hummelstown Fine Grind Plant; 2005-12-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Oldcastle Industrial Minerals → Hummelstown Fine Grind Plant; 2006-05-02 to 2009-03-10; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Oldcastle Industrial Minerals; 2006-05-02 to 2009-03-10; source msha-controller-operator-history
- **operator_operates_mine:** Pennsy Supply Inc. → Hummelstown Fine Grind Plant; 2009-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Pennsy Supply Inc.; 2009-03-11 to current/open; source msha-controller-operator-history