# Relationship history for MSHA mine 4600018

Current hierarchy: **William  Snyder; David  Snyder → R B S INC → GREYSTONE QUARRY AND 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:** R B S Inc → GREYSTONE QUARRY AND PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ronald B  Snyder → GREYSTONE QUARRY AND PLANT; 1950-01-01 to 2022-01-17; source msha-controller-operator-history
- **controller_controls_operator:** Ronald B  Snyder → R B S Inc; 1950-01-01 to 2022-01-17; source msha-controller-operator-history
- **controller_controls_mine:** David  Snyder et al → GREYSTONE QUARRY AND PLANT; 2022-01-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Snyder et al → R B S Inc; 2022-01-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Snyder et al → R B S Inc; 2022-01-18 to current/open; source msha-controller-operator-history