# Relationship history for MSHA mine 4104627

Current hierarchy: **Charles C  Mills → 90 West Contractors Ltd → 90 West Base Pit**

- 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:** Charles C  Mills → 90 West Base Pit; 1991-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** 90 West Contractors Ltd → 90 West Base Pit; 2006-11-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles C  Mills → 90 West Contractors Ltd; 2006-11-07 to current/open; source msha-controller-operator-history