# Relationship history for MSHA mine 4702918

Current hierarchy: **Minnesota Mining & Manufacturing Company → 3M Company → 3M - Downtown Plant**

- 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:** Minnesota Mining & Manufacturing Company → 3M - Downtown Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** 3M Company → 3M - Downtown Plant; 1990-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Minnesota Mining & Manufacturing Company → 3M Company; 1990-12-01 to current/open; source msha-controller-operator-history