# Relationship history for MSHA mine 4300711

Current hierarchy: **Harry W  Hart → Northeast Material Group, LLC → NEMG Graniteville Quarry**

- 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:** Northeast Material Group, LLC → NEMG Graniteville Quarry; 2010-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harry W  Hart et al → NEMG Graniteville Quarry; 2010-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harry W  Hart et al → Northeast Material Group, LLC; 2010-04-30 to current/open; source msha-controller-operator-history