# Relationship history for MSHA mine 4702753

Current hierarchy: **Raymond J  Michels → Michels Sand & Gravel → Michels Sand & Gravel M&40 Pit**

- 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:** Michels Sand & Gravel → Michels Sand & Gravel M&40 Pit; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Raymond J  Michels → Michels Sand & Gravel M&40 Pit; 1983-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Raymond J  Michels → Michels Sand & Gravel; 1983-04-01 to current/open; source msha-controller-operator-history