# Relationship history for MSHA mine 1001552

Current hierarchy: **Hecla Mining Company → Hecla Mining Company → GROUSE CREEK UNIT**

- 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:** Hecla Mining Company → GROUSE CREEK UNIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sunbeam Mining Corp → GROUSE CREEK UNIT; 1981-07-01 to 1989-05-04; source msha-controller-operator-history
- **controller_controls_mine:** Geodome Resources Ltd → GROUSE CREEK UNIT; 1981-07-01 to 1989-05-04; source msha-controller-operator-history
- **controller_controls_operator:** Geodome Resources Ltd → Sunbeam Mining Corp; 1981-07-01 to 1989-05-04; source msha-controller-operator-history
- **operator_operates_mine:** Grouse Creek Mining Inc → GROUSE CREEK UNIT; 1989-05-05 to 1991-06-26; source msha-controller-operator-history
- **controller_controls_mine:** Coca Mines Inc → GROUSE CREEK UNIT; 1989-05-05 to 1991-06-26; source msha-controller-operator-history
- **controller_controls_operator:** Coca Mines Inc → Grouse Creek Mining Inc; 1989-05-05 to 1991-06-26; source msha-controller-operator-history
- **operator_operates_mine:** Hecla Mining Company → GROUSE CREEK UNIT; 1991-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hecla Mining Company → Hecla Mining Company; 1991-06-27 to current/open; source msha-controller-operator-history