# Relationship history for MSHA mine 3900135

Current hierarchy: **Potter County Highway Department → Potter County Highway Department → Potter Couty Mines Or Potter Cty 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Potter County Highway Department → Potter Couty Mines Or Potter Cty Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Potter County Highway Department → Potter Couty Mines Or Potter Cty Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potter County Highway Department → Potter County Highway Department; 1950-01-01 to current/open; source msha-controller-operator-history