# Relationship history for MSHA mine 3200954

Current hierarchy: **Duffy  Froemke → Froemke Excavating → Froemke Gravel 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:** Froemke Excavating → Froemke Gravel Pit; 2012-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Duffy  Froemke → Froemke Gravel Pit; 2012-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duffy  Froemke → Froemke Excavating; 2012-04-10 to current/open; source msha-controller-operator-history