# Relationship history for MSHA mine 4406872

Current hierarchy: **Alpha Natural Resources, Inc. → Knox Creek Coal Corporation → Kennedy #2**

- 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:** United  Company → Kennedy #2; 1987-04-16 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Knox Creek Coal Corp → Kennedy #2; 1997-04-01 to 1997-08-25; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Knox Creek Coal Corp; 1997-04-01 to 1997-08-25; source msha-controller-operator-history
- **operator_operates_mine:** Knox Creek Coal Corporation → Kennedy #2; 1997-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Kennedy #2; 1997-08-26 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Knox Creek Coal Corporation; 1997-08-26 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Kennedy #2; 2011-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Knox Creek Coal Corporation; 2011-06-01 to current/open; source msha-controller-operator-history