# Relationship history for MSHA mine 2300714

Current hierarchy: **A M Mount Sand & Gravel → A M Mount Sand & Gravel → Mount Sand & Gravel Pit & Plant**

- 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:** A M Mount Sand & Gravel → Mount Sand & Gravel Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** A M Mount Sand & Gravel → Mount Sand & Gravel Pit & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** A M Mount Sand & Gravel → A M Mount Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history