# Relationship history for MSHA mine 1901186

Current hierarchy: **J G MacLellan Concrete Company Inc → Granite State Concrete Company Inc → Granite State Concrete Company Inc**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** J G MacLellan Concrete Company Inc → Granite State Concrete Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Granite State Concrete Company Inc → Granite State Concrete Company Inc; 2009-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** J G MacLellan Concrete Company Inc → Granite State Concrete Company Inc; 2009-04-03 to current/open; source msha-controller-operator-history