# Relationship history for MSHA mine 3401059

Current hierarchy: **Murphy James C → Murphy & Perkins Ready Mixed Concrete Company → Mustang No 1 Sand Plant**

- 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

- **operator_operates_mine:** Murphy & Perkins Ready Mixed Concrete Company → Mustang No 1 Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Murphy James C → Mustang No 1 Sand Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Murphy James C → Murphy & Perkins Ready Mixed Concrete Company; 1950-01-01 to current/open; source msha-controller-operator-history