# Relationship history for MSHA mine 2002591

Current hierarchy: **Roland H  Huhtala → R H Huhtala Construction → Gogebic County Pits**

- 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

- **controller_controls_mine:** Roland H  Huhtala → Gogebic County Pits; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R H Huhtala Construction → Gogebic County Pits; 1980-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roland H  Huhtala → R H Huhtala Construction; 1980-07-01 to current/open; source msha-controller-operator-history