# Relationship history for MSHA mine 3606459

Current hierarchy: **Polcovich John → Polcovich Coal Company → Seven Foot No 3 Slope**

- 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

- **controller_controls_mine:** Polcovich John → Seven Foot No 3 Slope; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Polcovich Coal Company → Seven Foot No 3 Slope; 1977-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Polcovich John → Polcovich Coal Company; 1977-07-01 to current/open; source msha-controller-operator-history