# Relationship history for MSHA mine 3304476

Current hierarchy: **Roy M  Roush → R Farm Sand & Gravel → R. FARM SAND AND GRAVEL**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** R Farm Sand & Gravel → R. FARM SAND AND GRAVEL; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roy M  Roush → R. FARM SAND AND GRAVEL; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roy M  Roush → R Farm Sand & Gravel; 2001-04-01 to current/open; source msha-controller-operator-history