# Relationship history for MSHA mine 4609192

Current hierarchy: **Core Natural Resources Inc → ICG TYGART VALLEY → LEER MINE**

- 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:** ICG Tygart Valley → LEER MINE; 2007-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** International Coal Group Inc (ICG) → LEER MINE; 2007-01-23 to 2011-06-14; source msha-controller-operator-history
- **controller_controls_operator:** International Coal Group Inc (ICG) → ICG Tygart Valley; 2007-01-23 to 2011-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Arch Resources Inc → LEER MINE; 2011-06-15 to 2025-01-13; source msha-controller-operator-history
- **controller_controls_operator:** Arch Resources Inc → ICG Tygart Valley; 2011-06-15 to 2025-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Core Natural Resources Inc → LEER MINE; 2025-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Core Natural Resources Inc → ICG Tygart Valley; 2025-01-14 to current/open; source msha-controller-operator-history