# Relationship history for MSHA mine 4300150

Current hierarchy: **Magris Performance Materials Inc → Magris Talc USA Inc → Ludlow 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:** Windsor Minerals Inc → Ludlow Mill; 1950-01-01 to 1989-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Johnson & Johnson → Ludlow Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson & Johnson → Windsor Minerals Inc; 1950-01-01 to 1989-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Ludlow Mill; 1988-05-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Windsor Minerals Corp → Ludlow Mill; 1989-06-05 to 1992-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Windsor Minerals Corp; 1989-06-05 to 1992-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Imerys Talc America Inc → Ludlow Mill; 1992-07-01 to 2021-02-16; source msha-controller-operator-history
- **controller_controls_mine:** Rio Tinto Group → Ludlow Mill; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Rio Tinto Group → Imerys Talc America Inc; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Ludlow Mill; 2011-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Imerys Talc America Inc; 2011-08-01 to 2021-02-16; source msha-controller-operator-history
- **operator_operates_mine:** Magris Talc USA Inc → Ludlow Mill; 2021-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Magris Performance Materials Inc → Ludlow Mill; 2021-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Magris Performance Materials Inc → Magris Talc USA Inc; 2021-02-17 to current/open; source msha-controller-operator-history