# Relationship history for MSHA mine 2501139

Current hierarchy: **Wells Marlin L → Fargo Gravel → York County 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:** Fargo Gravel → York County Pit; 1992-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wells Marlin L → York County Pit; 1992-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wells Marlin L → Fargo Gravel; 1992-07-01 to current/open; source msha-controller-operator-history
