# Relationship history for MSHA mine 3101959

Current hierarchy: **Bell Clyde Boyce → Bell Construction Company Inc → Bell Sand Pits**

- 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:** Bell Construction Company Inc → Bell Sand Pits; 1983-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bell Clyde Boyce → Bell Sand Pits; 1983-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bell Clyde Boyce → Bell Construction Company Inc; 1983-06-01 to current/open; source msha-controller-operator-history