# Relationship history for MSHA mine 3609172

Current hierarchy: **James P  Duffy → Duffy Inc → Port Alleghany 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:** D & D Stone → Port Alleghany Mine; 2003-10-10 to 2005-10-27; source msha-controller-operator-history
- **controller_controls_mine:** James P  Duffy → Port Alleghany Mine; 2003-10-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James P  Duffy → D & D Stone; 2003-10-10 to 2005-10-27; source msha-controller-operator-history
- **operator_operates_mine:** Duffy Inc → Port Alleghany Mine; 2005-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James P  Duffy → Port Alleghany Mine; 2005-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James P  Duffy → Duffy Inc; 2005-10-28 to current/open; source msha-controller-operator-history