# Relationship history for MSHA mine 1201713

Current hierarchy: **CRH PLC → Mulzer Crushed Stone Inc → Eckerty Underground Mine**

- 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:** Bart  Mulzer et al → Eckerty Underground Mine; 1950-01-01 to 2017-02-09; source msha-controller-operator-history
- **operator_operates_mine:** Mulzer Crushed Stone Inc → Eckerty Underground Mine; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bart  Mulzer et al → Mulzer Crushed Stone Inc; 1979-01-01 to 2017-02-09; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Eckerty Underground Mine; 2017-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Mulzer Crushed Stone Inc; 2017-02-10 to current/open; source msha-controller-operator-history