# Relationship history for MSHA mine 3100430

Current hierarchy: **Hurst Billy A → Hurst Concrete Products Company Inc → Hurst 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:** Hurst Concrete Products Company Inc → Hurst Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hurst Billy A → Hurst Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hurst Billy A → Hurst Concrete Products Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history