# Relationship history for MSHA mine 2104018

Current hierarchy: **Brad M Zubke → Zubke Gravel → Zubke 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:** Zubke Gravel → Zubke Gravel; 2021-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brad M Zubke → Zubke Gravel; 2021-10-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brad M Zubke → Zubke Gravel; 2021-10-20 to current/open; source msha-controller-operator-history