# Relationship history for MSHA mine 3605380

Current hierarchy: **Griffiths Thomas J → Selkirk Mining Company → Silverton Stripping**

- 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:** Selkirk Mining Company → Silverton Stripping; 1974-12-01 to 1978-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Joseph  Kovaleski → Silverton Stripping; 1974-12-01 to 1978-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Joseph  Kovaleski → Selkirk Mining Company; 1974-12-01 to 1978-08-09; source msha-controller-operator-history
- **operator_operates_mine:** Selkirk Mining Company → Silverton Stripping; 1978-08-10 to 1989-06-12; source msha-controller-operator-history
- **controller_controls_mine:** Ryon Richard B & Richard F → Silverton Stripping; 1978-08-10 to 1989-06-12; source msha-controller-operator-history
- **controller_controls_operator:** Ryon Richard B & Richard F → Selkirk Mining Company; 1978-08-10 to 1989-06-12; source msha-controller-operator-history
- **operator_operates_mine:** Selkirk Mining Company → Silverton Stripping; 1989-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Griffiths Thomas J → Silverton Stripping; 1989-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Griffiths Thomas J → Selkirk Mining Company; 1989-06-13 to current/open; source msha-controller-operator-history