# Relationship history for MSHA mine 5001574

Current hierarchy: **Gerald  Hassel → R B Gravel Company → R B 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** R B Gravel Company → R B Gravel; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gerald  Hassel → R B Gravel; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gerald  Hassel → R B Gravel Company; 1988-08-01 to current/open; source msha-controller-operator-history