# Relationship history for MSHA mine 0301839

Current hierarchy: **G W  Johnson → Gee & Dee Crystal → Brewster Mountain**

- 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

- **operator_operates_mine:** Gee & Dee Crystal → Brewster Mountain; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** G W  Johnson → Brewster Mountain; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** G W  Johnson → Gee & Dee Crystal; 2000-10-01 to current/open; source msha-controller-operator-history