# Relationship history for MSHA mine 3301610

Current hierarchy: **Rogers Group Inc → Rogers Group Inc → NORWALK SAND & GRAVEL**

- 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

- **controller_controls_mine:** Rogers Group Inc → NORWALK SAND & GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Price Companies → NORWALK SAND & GRAVEL; 1950-01-01 to 1990-09-11; source msha-controller-operator-history
- **controller_controls_mine:** Robert C Price → NORWALK SAND & GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert C Price → Price Companies; 1950-01-01 to 1990-09-11; source msha-controller-operator-history
- **operator_operates_mine:** Rogers Group Inc → NORWALK SAND & GRAVEL; 1990-09-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rogers Group Inc → Rogers Group Inc; 1990-09-12 to current/open; source msha-controller-operator-history