# Relationship history for MSHA mine 2901906

Current hierarchy: **Cyprus Amax Minerals Company → Cyprus Pinos Altos Corp → Cyprus Pinos Altos Corporation**

- 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

- **operator_operates_mine:** Boliden Minerals Inc → Cyprus Pinos Altos Corporation; 1983-01-01 to 1987-06-01; source msha-controller-operator-history
- **controller_controls_mine:** Vannman Lars E → Cyprus Pinos Altos Corporation; 1983-01-01 to 1987-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Vannman Lars E → Boliden Minerals Inc; 1983-01-01 to 1987-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Pinos Altos Corp → Cyprus Pinos Altos Corporation; 1987-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Cyprus Pinos Altos Corporation; 1987-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Pinos Altos Corp; 1987-06-02 to current/open; source msha-controller-operator-history