# Relationship history for MSHA mine 0404689

Current hierarchy: **Nova Extraction Technologies & Lewis D Hall Est → Nova Extraction Technologies & Lewis D Hall Est → Benson Mine**

- 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:** Nova Extraction Technologies & Lewis D Hall Est → Benson Mine; 1984-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Nova Extraction Technologies & Lewis D Hall Est → Benson Mine; 1984-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nova Extraction Technologies & Lewis D Hall Est → Nova Extraction Technologies & Lewis D Hall Est; 1984-02-01 to current/open; source msha-controller-operator-history