# Relationship history for MSHA mine 4200392

Current hierarchy: **Mohr Brad → Mohr Sand & Gravel Company → Hyrum 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Cache Concrete Consolidated → Hyrum Pit; 1950-01-01 to 1984-07-12; source msha-controller-operator-history
- **controller_controls_mine:** Mohr Robert Dr → Hyrum Pit; 1950-01-01 to 1984-07-12; source msha-controller-operator-history
- **controller_controls_operator:** Mohr Robert Dr → Cache Concrete Consolidated; 1950-01-01 to 1984-07-12; source msha-controller-operator-history
- **operator_operates_mine:** Mohr Sand & Gravel Company → Hyrum Pit; 1984-07-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mohr Brad → Hyrum Pit; 1984-07-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mohr Brad → Mohr Sand & Gravel Company; 1984-07-13 to current/open; source msha-controller-operator-history