# Relationship history for MSHA mine 3503433

Current hierarchy: **Imerys S A → Imerys Perlite USA, Inc. → Tucker Hill 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

- **controller_controls_mine:** Alleghany Corp → Tucker Hill Mill; 1992-11-16 to 2005-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Cornerstone Industrial Minerals Corp Usa → Tucker Hill Mill; 1996-09-01 to 1999-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Atlas Corp → Tucker Hill Mill; 1996-09-01 to 1999-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Atlas Corp → Cornerstone Industrial Minerals Corp Usa; 1996-09-01 to 1999-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Cornerstone Industrial Minerals → Tucker Hill Mill; 1999-02-01 to 2020-04-18; source msha-controller-operator-history
- **controller_controls_mine:** Seven Peaks Mining → Tucker Hill Mill; 1999-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Seven Peaks Mining → Cornerstone Industrial Minerals; 1999-02-01 to 2020-04-18; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Tucker Hill Mill; 2005-07-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Imerys Perlite USA, Inc. → Tucker Hill Mill; 2020-04-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alleghany Corp → Imerys Perlite USA, Inc.; 2020-04-19 to 2005-07-14; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Imerys Perlite USA, Inc.; 2020-04-19 to current/open; source msha-controller-operator-history