# Relationship history for MSHA mine 0102718

Current hierarchy: **Johnson Bobby R → Brewton Sand & Gravel Inc → Brewton Sand & Gravel Incorporated**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Brewton Sand & Gravel Inc → Brewton Sand & Gravel Incorporated; 1987-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Bobby R → Brewton Sand & Gravel Incorporated; 1987-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Bobby R → Brewton Sand & Gravel Inc; 1987-01-01 to current/open; source msha-controller-operator-history