# Relationship history for MSHA mine 3901511

Current hierarchy: **David J  Hall → H & S Sand & Gravel → H & S Sand and 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** H & S Sand & Gravel → H & S Sand and Gravel Inc; 2005-09-20 to 2011-10-21; source msha-controller-operator-history
- **controller_controls_mine:** David J  Hall → H & S Sand and Gravel Inc; 2005-09-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Hall → H & S Sand & Gravel; 2005-09-20 to 2011-10-21; source msha-controller-operator-history
- **operator_operates_mine:** H & S Sand & Gravel → H & S Sand and Gravel Inc; 2011-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David J  Hall → H & S Sand and Gravel Inc; 2011-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Hall → H & S Sand & Gravel; 2011-10-22 to current/open; source msha-controller-operator-history