# Relationship history for MSHA mine 2400163

Current hierarchy: **Magris Performance Materials Inc → Magris Talc USA, Inc. → Yellowstone 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

- **operator_operates_mine:** Cyprus Industrial Minerals Company → Yellowstone Mine; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Mines Corp → Yellowstone Mine; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Mines Corp → Cyprus Industrial Minerals Company; 1950-01-01 to 1980-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Industrial Minerals Company → Yellowstone Mine; 1980-09-22 to 1992-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Yellowstone Mine; 1980-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Industrial Minerals Company; 1980-09-22 to 1992-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Imerys Talc Incorporated → Yellowstone Mine; 1992-07-01 to 2021-02-16; source msha-controller-operator-history
- **controller_controls_mine:** Rio Tinto Group → Yellowstone Mine; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Rio Tinto Group → Imerys Talc Incorporated; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Yellowstone Mine; 2011-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Imerys Talc Incorporated; 2011-08-01 to 2021-02-16; source msha-controller-operator-history
- **operator_operates_mine:** Magris Talc USA, Inc. → Yellowstone Mine; 2021-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Magris Performance Materials Inc → Yellowstone Mine; 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