# Relationship history for MSHA mine 3302868

Current hierarchy: **Colas S A → Barrett Paving Materials Inc → Ludlow 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Ludlow Stone Inc → Ludlow Quarry; 1950-01-01 to 1992-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Northwood Group Inc → Ludlow Quarry; 1950-01-01 to 1992-01-15; source msha-controller-operator-history
- **controller_controls_operator:** Northwood Group Inc → Ludlow Stone Inc; 1950-01-01 to 1992-01-15; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → Ludlow Quarry; 1979-12-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Barrett Paving Materials Inc → Ludlow Quarry; 1992-01-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → Barrett Paving Materials Inc; 1992-01-16 to current/open; source msha-controller-operator-history