# Relationship history for MSHA mine 4300537

Current hierarchy: **Robert  Williams; Robert R  Williams → Williams & Williams Slate Company Inc → N. POULTNEY 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Williams & Williams Slate Company Inc → N. POULTNEY QUARRY; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert R  Williams et al → N. POULTNEY QUARRY; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert R  Williams et al → Williams & Williams Slate Company Inc; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Williams et al → Williams & Williams Slate Company Inc; 1999-09-01 to current/open; source msha-controller-operator-history