# Relationship history for MSHA mine 0900928

Current hierarchy: **Engelhard Corp → Engelhard Kaolin Corp → Freeman 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:** Freeport Minerals Company → Freeman Mine; 1950-01-01 to 1985-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Freeport Kaolin Company → Freeman Mine; 1980-07-01 to 1985-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Freeport Minerals Company → Freeport Kaolin Company; 1980-07-01 to 1985-02-12; source msha-controller-operator-history
- **operator_operates_mine:** Engelhard Kaolin Corp → Freeman Mine; 1985-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Engelhard Corp → Freeman Mine; 1985-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Engelhard Corp → Engelhard Kaolin Corp; 1985-02-13 to current/open; source msha-controller-operator-history