# Relationship history for MSHA mine 0500417

Current hierarchy: **Echo Bay Mines Ltd → Sunnyside Gold Corp → Sunnyside Mine/Mayflower 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Standard Metals Corp → Sunnyside Mine/Mayflower Mill; 1950-01-01 to 1985-11-18; source msha-controller-operator-history
- **controller_controls_mine:** Gresov Boris → Sunnyside Mine/Mayflower Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gresov Boris → Standard Metals Corp; 1950-01-01 to 1985-11-18; source msha-controller-operator-history
- **operator_operates_mine:** Sunnyside Gold Corp → Sunnyside Mine/Mayflower Mill; 1985-11-19 to 1988-06-09; source msha-controller-operator-history
- **controller_controls_mine:** Echo Bay Mines Ltd → Sunnyside Mine/Mayflower Mill; 1985-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Echo Bay Mines Ltd → Sunnyside Gold Corp; 1985-11-19 to 1988-06-09; source msha-controller-operator-history
- **operator_operates_mine:** Washington Mining Company → Sunnyside Mine/Mayflower Mill; 1988-06-10 to 1992-03-17; source msha-controller-operator-history
- **controller_controls_mine:** Alta Gold Co-Washington Mining Co & Echo Bay Mines → Sunnyside Mine/Mayflower Mill; 1988-06-10 to 1992-03-17; source msha-controller-operator-history
- **controller_controls_operator:** Alta Gold Co-Washington Mining Co & Echo Bay Mines → Washington Mining Company; 1988-06-10 to 1992-03-17; source msha-controller-operator-history
- **operator_operates_mine:** Sunnyside Gold Corp → Sunnyside Mine/Mayflower Mill; 1992-03-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Echo Bay Mines Ltd → Sunnyside Gold Corp; 1992-03-18 to current/open; source msha-controller-operator-history