# Relationship history for MSHA mine 1301810

Current hierarchy: **Woodbury County → Woodbury County Highway Department → Railroad 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:** Woodbury County Highway Department → Railroad Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Woodbury County → Railroad Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Woodbury County → Woodbury County Highway Department; 1950-01-01 to current/open; source msha-controller-operator-history