# Relationship history for MSHA mine 3606170

Current hierarchy: **Bernas Henry J → H B Trucking Company → Burnside Strip**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** H B Trucking Company → Burnside Strip; 1976-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bernas Henry J → Burnside Strip; 1976-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bernas Henry J → H B Trucking Company; 1976-07-20 to current/open; source msha-controller-operator-history