# Relationship history for MSHA mine 4202215

Current hierarchy: **Imerys S A → Harborlite Corporation → Black Springs 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

- **controller_controls_mine:** Alleghany Corp → Black Springs Mine; 1992-11-16 to 2005-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Pearl Queen Perlite Corp → Black Springs Mine; 1998-08-01 to 1999-12-31; source msha-controller-operator-history
- **controller_controls_mine:** O Jay  Gatten → Black Springs Mine; 1998-08-01 to 1999-12-31; source msha-controller-operator-history
- **controller_controls_operator:** O Jay  Gatten → Pearl Queen Perlite Corp; 1998-08-01 to 1999-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Basin Perlite Company → Black Springs Mine; 2000-01-01 to 2005-07-14; source msha-controller-operator-history
- **controller_controls_mine:** William R  Wilson → Black Springs Mine; 2000-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William R  Wilson → Basin Perlite Company; 2000-01-01 to 2005-07-14; source msha-controller-operator-history
- **operator_operates_mine:** Harborlite Corporation → Black Springs Mine; 2005-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alleghany Corp → Harborlite Corporation; 2005-07-15 to 2005-07-14; source msha-controller-operator-history
- **controller_controls_mine:** Imerys S A → Black Springs Mine; 2005-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Imerys S A → Harborlite Corporation; 2005-07-15 to current/open; source msha-controller-operator-history