# Relationship history for MSHA mine 3607704

Current hierarchy: **Burgettstown Area School District-Pa → Burgettstown Area School District → Junior/Senior High School Mine**

- 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:** Burgettstown Area School District → Junior/Senior High School Mine; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Burgettstown Area School District-Pa → Junior/Senior High School Mine; 1985-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Burgettstown Area School District-Pa → Burgettstown Area School District; 1985-06-01 to current/open; source msha-controller-operator-history