# Relationship history for MSHA mine 2402425

Current hierarchy: **Robyn  Duffy → Montana Solid Rock Quarry, Inc → Montana Solid Rock Quarry #1**

- 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:** Montana Solid Rock Quarry, Inc → Montana Solid Rock Quarry #1; 2005-09-02 to 2014-09-22; source msha-controller-operator-history
- **controller_controls_mine:** Paul W  Chambers → Montana Solid Rock Quarry #1; 2005-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul W  Chambers → Montana Solid Rock Quarry, Inc; 2005-09-02 to 2014-09-22; source msha-controller-operator-history
- **operator_operates_mine:** Montana Solid Rock Quarry, Inc → Montana Solid Rock Quarry #1; 2014-09-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas  Duffy et al → Montana Solid Rock Quarry #1; 2014-09-23 to 2026-06-08; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  Duffy et al → Montana Solid Rock Quarry, Inc; 2014-09-23 to 2026-06-08; source msha-controller-operator-history
- **controller_controls_operator:** Robyn  Duffy et al → Montana Solid Rock Quarry, Inc; 2014-09-23 to 2026-06-08; source msha-controller-operator-history
- **controller_controls_mine:** Robyn  Duffy → Montana Solid Rock Quarry #1; 2026-06-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robyn  Duffy → Montana Solid Rock Quarry, Inc; 2026-06-09 to current/open; source msha-controller-operator-history