# Relationship history for MSHA mine 2901342

Current hierarchy: **Ribble Contracting Inc & Interwest Ltd → Westside Materials → Westside Materials**

- 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:** Ribble Contracting Inc → Westside Materials; 1950-01-01 to 1987-01-20; source msha-controller-operator-history
- **controller_controls_mine:** Norman C  Ribble → Westside Materials; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Norman C  Ribble → Ribble Contracting Inc; 1950-01-01 to 1987-01-20; source msha-controller-operator-history
- **operator_operates_mine:** Westside Materials → Westside Materials; 1987-01-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ribble Contracting Inc & Interwest Ltd → Westside Materials; 1987-01-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ribble Contracting Inc & Interwest Ltd → Westside Materials; 1987-01-21 to current/open; source msha-controller-operator-history