# Relationship history for MSHA mine 3304493

Current hierarchy: **CRH PLC → Shelly Materials Inc → Forest Quarry**

- 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:** James E  Duff → Forest Quarry; 1950-01-01 to 2014-09-22; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Forest Quarry; 2000-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C.E. DUFF & SON INC. → Forest Quarry; 2002-01-30 to 2005-06-27; source msha-controller-operator-history
- **controller_controls_operator:** James E  Duff → C.E. DUFF & SON INC.; 2002-01-30 to 2005-06-27; source msha-controller-operator-history
- **operator_operates_mine:** Shelly Materials Inc → Forest Quarry; 2005-06-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Shelly Materials Inc; 2005-06-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James D  Duff et al → Forest Quarry; 2014-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James D  Duff et al → C.E. DUFF & SON INC.; 2014-09-23 to 2005-06-27; source msha-controller-operator-history
- **controller_controls_operator:** James S  Duff et al → C.E. DUFF & SON INC.; 2014-09-23 to 2005-06-27; source msha-controller-operator-history