# Relationship history for MSHA mine 4701168

Current hierarchy: **Lang Don → Lang Engineering Company Inc → Wuttke Pit And Portable Mill**

- 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:** Lang Engineering Company Inc → Wuttke Pit And Portable Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lang Don → Wuttke Pit And Portable Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lang Don → Lang Engineering Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history