# Relationship history for MSHA mine 2200429

Current hierarchy: **Bell D B → D B Bell Company → Bell Pit**

- 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:** D B Bell Company → Bell Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bell D B → Bell Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bell D B → D B Bell Company; 1950-01-01 to current/open; source msha-controller-operator-history