# Relationship history for MSHA mine 4608844

Current hierarchy: **Alpha Natural Resources Holdings, Inc → Independence Coal Company Inc → Middle Cedar Grove**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Massey Energy Company → Middle Cedar Grove; 1991-12-01 to 2011-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Independence Coal Company Inc → Middle Cedar Grove; 2000-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Independence Coal Company Inc; 2000-07-01 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Middle Cedar Grove; 2011-06-01 to 2016-07-25; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Independence Coal Company Inc; 2011-06-01 to 2016-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources Holdings, Inc → Middle Cedar Grove; 2016-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources Holdings, Inc → Independence Coal Company Inc; 2016-07-26 to current/open; source msha-controller-operator-history