# Relationship history for MSHA mine 3301217

Current hierarchy: **B M I Inc → Gunning Refractories Inc → South Webster 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Gunning Refractories Inc → South Webster Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** B M I Inc → South Webster Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** B M I Inc → Gunning Refractories Inc; 1950-01-01 to current/open; source msha-controller-operator-history