# Relationship history for MSHA mine 4002497

Current hierarchy: **Potter George → Fen Coal Inc → No 1 Surface**

- 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:** Fen Coal Inc → No 1 Surface; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Potter George → No 1 Surface; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Potter George → Fen Coal Inc; 1979-01-01 to current/open; source msha-controller-operator-history