# Relationship history for MSHA mine 4406921

Current hierarchy: **Alpha Natural Resources, Inc. → Mill Branch Coal Corp → Whitley Fork Surface 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

- **controller_controls_mine:** Cumberland Resources Corporation → Whitley Fork Surface Mine; 1996-12-01 to 2010-04-18; source msha-controller-operator-history
- **operator_operates_mine:** Tri-State Leasing Corp → Whitley Fork Surface Mine; 1998-07-01 to 2012-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Steven R  Mullins → Whitley Fork Surface Mine; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven R  Mullins → Tri-State Leasing Corp; 1998-07-01 to 2012-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Whitley Fork Surface Mine; 2010-04-19 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Alpha Natural Resources, Inc. → Whitley Fork Surface Mine; 2011-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mill Branch Coal Corp → Whitley Fork Surface Mine; 2013-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alpha Natural Resources, Inc. → Mill Branch Coal Corp; 2013-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Mill Branch Coal Corp; 2013-01-01 to 2011-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Cumberland Resources Corporation → Mill Branch Coal Corp; 2013-01-01 to 2010-04-18; source msha-controller-operator-history