# Relationship history for MSHA mine 3401185

Current hierarchy: **Barnett Charles → Barnett Trucking Service → Pierce 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Hurst Sand & Gravel → Pierce Pit; 1979-01-01 to 1991-06-03; source msha-controller-operator-history
- **controller_controls_mine:** Hurst Robert & L R → Pierce Pit; 1979-01-01 to 1991-06-03; source msha-controller-operator-history
- **controller_controls_operator:** Hurst Robert & L R → Hurst Sand & Gravel; 1979-01-01 to 1991-06-03; source msha-controller-operator-history
- **operator_operates_mine:** Barnett Trucking Service → Pierce Pit; 1991-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barnett Charles → Pierce Pit; 1991-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barnett Charles → Barnett Trucking Service; 1991-06-04 to current/open; source msha-controller-operator-history