# Relationship history for MSHA mine 3304671

Current hierarchy: **Mary J  Brown → Valley Mining,Inc → Mobile Auger #2  Unit 53**

- 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:** Mary J  Brown → Mobile Auger #2  Unit 53; 1972-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Valley Mining,Inc → Mobile Auger #2  Unit 53; 2011-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mary J  Brown → Valley Mining,Inc; 2011-07-01 to current/open; source msha-controller-operator-history