# Relationship history for MSHA mine 4608690

Current hierarchy: **Brent M  Cook → Flat Ridge Corp → Simpson Hollow Reprocessing Site**

- 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:** Flat Ridge Corp → Simpson Hollow Reprocessing Site; 1998-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brent M  Cook → Simpson Hollow Reprocessing Site; 1998-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent M  Cook → Flat Ridge Corp; 1998-01-01 to current/open; source msha-controller-operator-history