# Relationship history for MSHA mine 3401290

Current hierarchy: **Hurst Robert G → Hurst Gravel → Hurst Gravel**

- 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:** Hoover City Gravel Company → Hurst Gravel; 1980-07-01 to 1983-03-13; source msha-controller-operator-history
- **controller_controls_mine:** Cast Cary → Hurst Gravel; 1980-07-01 to 1983-03-13; source msha-controller-operator-history
- **controller_controls_operator:** Cast Cary → Hoover City Gravel Company; 1980-07-01 to 1983-03-13; source msha-controller-operator-history
- **operator_operates_mine:** Hurst Gravel → Hurst Gravel; 1983-03-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hurst Robert G → Hurst Gravel; 1983-03-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hurst Robert G → Hurst Gravel; 1983-03-14 to current/open; source msha-controller-operator-history