# Relationship history for MSHA mine 0404872

Current hierarchy: **Hecla Mining Company; MK Gold Co → American Girl Mining Joint Venture → AMERICAN GIRL SURFACE 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:** MK Gold Co  et al → AMERICAN GIRL SURFACE MINE; 1986-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Girl Mining Joint Venture → AMERICAN GIRL SURFACE MINE; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MK Gold Co  et al → American Girl Mining Joint Venture; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hecla Mining Company  et al → American Girl Mining Joint Venture; 1987-03-01 to current/open; source msha-controller-operator-history