# Relationship history for MSHA mine 4400044

Current hierarchy: **Carmeuse Holding SA → O-N Minerals (Chemstone Company) → Winchester 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

- **operator_operates_mine:** W S Frey Company Inc → Winchester Plant; 1950-01-01 to 1999-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Wm S  Frey → Winchester Plant; 1950-01-01 to 1999-03-17; source msha-controller-operator-history
- **controller_controls_operator:** Wm S  Frey → W S Frey Company Inc; 1950-01-01 to 1999-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Oglebay Norton Company → Winchester Plant; 1998-06-22 to 2008-02-12; source msha-controller-operator-history
- **operator_operates_mine:** O-N Minerals (Chemstone Company) → Winchester Plant; 1999-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Oglebay Norton Company → O-N Minerals (Chemstone Company); 1999-03-18 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Carmeuse Holding SA → Winchester Plant; 2008-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carmeuse Holding SA → O-N Minerals (Chemstone Company); 2008-02-13 to current/open; source msha-controller-operator-history