# Relationship history for MSHA mine 0600609

Current hierarchy: **Anderson John → A & A Truck Brokers → J & T Sand & Gravel 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:** A & A Truck Brokers → J & T Sand & Gravel Pit; 1985-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Anderson John → J & T Sand & Gravel Pit; 1985-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Anderson John → A & A Truck Brokers; 1985-07-01 to current/open; source msha-controller-operator-history