# Relationship history for MSHA mine 4407180

Current hierarchy: **Alpha Natural Resources, Inc. → Knox Creek Coal Corp. → Hurricane Branch Strip #1**

- 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

- **controller_controls_mine:** Massey Energy Company → Hurricane Branch Strip #1; 1997-08-26 to 2011-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Knox Creek Coal Corp. → Hurricane Branch Strip #1; 2006-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Knox Creek Coal Corp.; 2006-07-31 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Hurricane Branch Strip #1; 2011-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Knox Creek Coal Corp.; 2011-06-01 to current/open; source msha-controller-operator-history