# Relationship history for MSHA mine 4700813

Current hierarchy: **Paul T  Ayres → Red Flint Sand & Gravel LLC → Industrial  Sand 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:** American Materials Corp → Industrial  Sand Plant; 1950-01-01 to 2004-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Paul T  Ayres → Industrial  Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul T  Ayres → American Materials Corp; 1950-01-01 to 2004-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Red Flint Sand & Gravel LLC → Industrial  Sand Plant; 2004-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Paul T  Ayres → Industrial  Sand Plant; 2004-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul T  Ayres → Red Flint Sand & Gravel LLC; 2004-12-15 to current/open; source msha-controller-operator-history