# Relationship history for MSHA mine 4406593

Current hierarchy: **Charles H  Gent → H B & B Equipment Company Inc → Mine #4**

- 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

- **controller_controls_mine:** Charles H  Gent → Mine #4; 1988-03-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H B & B Equipment Company Inc → Mine #4; 1990-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles H  Gent → H B & B Equipment Company Inc; 1990-07-01 to current/open; source msha-controller-operator-history