# Relationship history for MSHA mine 2000756

Current hierarchy: **Genoak Materials Inc → Tri-City Aggregates Inc → PIONEER CRUSHER**

- 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:** Tri-City Aggregates Inc → PIONEER CRUSHER; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Genoak Materials Inc → PIONEER CRUSHER; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Genoak Materials Inc → Tri-City Aggregates Inc; 1950-01-01 to current/open; source msha-controller-operator-history