# Relationship history for MSHA mine 0300257

Current hierarchy: **OYAK Group → Almatis Inc → Arkansas Operations Mill**

- 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

- **operator_operates_mine:** Alcoa World Alumina Llc → Arkansas Operations Mill; 1950-01-01 to 2004-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Alcoa Inc → Arkansas Operations Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alcoa Inc → Alcoa World Alumina Llc; 1950-01-01 to 2004-02-29; source msha-controller-operator-history
- **operator_operates_mine:** Almatis Inc → Arkansas Operations Mill; 2004-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Almatis Holdings 1 BV → Arkansas Operations Mill; 2004-03-01 to 2015-10-23; source msha-controller-operator-history
- **controller_controls_operator:** Almatis Holdings 1 BV → Almatis Inc; 2004-03-01 to 2015-10-23; source msha-controller-operator-history
- **controller_controls_mine:** OYAK Group → Arkansas Operations Mill; 2015-10-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** OYAK Group → Almatis Inc; 2015-10-24 to current/open; source msha-controller-operator-history