# Relationship history for MSHA mine 4300410

Current hierarchy: **Imerys S A → Luzenac America, Inc. → Troy 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:** Troy Minerals Company → Troy Mine; 1987-06-01 to 1988-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Demers Lucien A & Michael P Chmielewski → Troy Mine; 1987-06-01 to 1991-01-23; source msha-controller-operator-history
- **controller_controls_operator:** Demers Lucien A & Michael P Chmielewski → Troy Minerals Company; 1987-06-01 to 1988-05-12; source msha-controller-operator-history
- **operator_operates_mine:** Green Mountain Talc Corp → Troy Mine; 1988-05-13 to 1988-08-11; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Troy Mine; 1988-05-13 to 1992-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Green Mountain Talc Corp; 1988-05-13 to 1988-08-11; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Troy Mine; 1988-05-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Troy Minerals Company → Troy Mine; 1988-08-12 to 1991-01-23; source msha-controller-operator-history
- **controller_controls_operator:** Demers Lucien A & Michael P Chmielewski → Troy Minerals Company; 1988-08-12 to 1991-01-23; source msha-controller-operator-history
- **operator_operates_mine:** Cyprus Windsor Minerals Corp → Troy Mine; 1991-01-24 to 1992-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Cyprus Windsor Minerals Corp; 1991-01-24 to 1992-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Luzenac America, Inc. → Troy Mine; 1992-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rio Tinto Group → Troy Mine; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Rio Tinto Group → Luzenac America, Inc.; 1992-07-01 to 2011-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Troy Mine; 2011-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Luzenac America, Inc.; 2011-08-01 to current/open; source msha-controller-operator-history