# Relationship history for MSHA mine 3002979

Current hierarchy: **James  Barker → Roanoke Sand & Gravel Corp → ROANOKE YAPHANK SAND & GRAVEL CO**

- 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

- **controller_controls_mine:** James  Barker → ROANOKE YAPHANK SAND & GRAVEL CO; 1984-12-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Roanoke Sand & Gravel Corp → ROANOKE YAPHANK SAND & GRAVEL CO; 1990-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Barker → Roanoke Sand & Gravel Corp; 1990-09-01 to current/open; source msha-controller-operator-history