# Relationship history for MSHA mine 2002929

Current hierarchy: **Barr Douglas T → Barr Sand & Gravel Inc → BARR SAND & GRAVEL INC.**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Barr Sand & Gravel Inc → BARR SAND & GRAVEL INC.; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barr Douglas T → BARR SAND & GRAVEL INC.; 1994-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barr Douglas T → Barr Sand & Gravel Inc; 1994-05-01 to current/open; source msha-controller-operator-history