# Relationship history for MSHA mine 0405903

Current hierarchy: **Albert  Ruiz → Fireman Rock & Nursery → A R Rock Quarry**

- 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:** Fireman Rock & Nursery → A R Rock Quarry; 2015-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Albert  Ruiz → A R Rock Quarry; 2015-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert  Ruiz → Fireman Rock & Nursery; 2015-06-17 to current/open; source msha-controller-operator-history