# Relationship history for MSHA mine 4103019

Current hierarchy: **Buzzi S p A → Alamo Cement Company → 1604 QUARRY & 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Buzzi S p A → 1604 QUARRY & PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alamo Cement Company Ltd → 1604 QUARRY & PLANT; 1980-06-01 to 2010-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Buzzi S p A → Alamo Cement Company Ltd; 1980-06-01 to 2010-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Alamo Cement Company → 1604 QUARRY & PLANT; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Buzzi S p A → 1604 QUARRY & PLANT; 2011-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Buzzi S p A → Alamo Cement Company; 2011-01-01 to current/open; source msha-controller-operator-history