# Relationship history for MSHA mine 4702942

Current hierarchy: **Paul T  Ayres → American Materials Corp → #753 ALLIS CHALMERS SCREEN 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

- **controller_controls_mine:** Paul T  Ayres → #753 ALLIS CHALMERS SCREEN PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Materials Corp → #753 ALLIS CHALMERS SCREEN PLANT; 1991-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul T  Ayres → American Materials Corp; 1991-10-01 to current/open; source msha-controller-operator-history