# Relationship history for MSHA mine 1800564

Current hierarchy: **Hutchison Brothers Excavating Company Inc → Eco-Rok Inc → Eco-Rok Incorporated**

- 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:** Eco-Rok Inc → Eco-Rok Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hutchison Brothers Excavating Company Inc → Eco-Rok Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hutchison Brothers Excavating Company Inc → Eco-Rok Inc; 1950-01-01 to current/open; source msha-controller-operator-history