# Relationship history for MSHA mine 5001267

Current hierarchy: **Hecla Mining Company → Hecla Greens Creek Mining Company → Hecla Greens Creek 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Greens Creek Mining Company → Hecla Greens Creek Mine; 1978-03-09 to 1988-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Amselco Minerals Inc-Exalas Resources Corp Et Al → Hecla Greens Creek Mine; 1978-03-09 to 1988-02-29; source msha-controller-operator-history
- **controller_controls_operator:** Amselco Minerals Inc-Exalas Resources Corp Et Al → Greens Creek Mining Company; 1978-03-09 to 1988-02-29; source msha-controller-operator-history
- **operator_operates_mine:** Greens Creek Mining Company → Hecla Greens Creek Mine; 1988-03-01 to 1989-06-29; source msha-controller-operator-history
- **controller_controls_mine:** British Petroleum Company PLC → Hecla Greens Creek Mine; 1988-03-01 to 1989-06-29; source msha-controller-operator-history
- **controller_controls_operator:** British Petroleum Company PLC → Greens Creek Mining Company; 1988-03-01 to 1989-06-29; source msha-controller-operator-history
- **operator_operates_mine:** Hecla Greens Creek Mining Company → Hecla Greens Creek Mine; 1989-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rio Tinto Group → Hecla Greens Creek Mine; 1989-06-30 to 2008-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Rio Tinto Group → Hecla Greens Creek Mining Company; 1989-06-30 to 2008-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Hecla Mining Company → Hecla Greens Creek Mine; 2008-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hecla Mining Company → Hecla Greens Creek Mining Company; 2008-04-24 to current/open; source msha-controller-operator-history