# Relationship history for MSHA mine 1800785

Current hierarchy: **Randolph G  Blanton → Chesapeake Materials LLC → Elk Mills 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

- **controller_controls_mine:** Randolph G  Blanton → Elk Mills Quarry; 2009-09-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chesapeake Materials LLC → Elk Mills Quarry; 2009-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Randolph G  Blanton → Chesapeake Materials LLC; 2009-10-20 to current/open; source msha-controller-operator-history