# Relationship history for MSHA mine 4609448

Current hierarchy: **White Forest Resources, Inc → South Fork Coal Co., LLC → Blue Knob 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:** Xinergy Ltd → Blue Knob Surface Mine; 2011-10-18 to 2016-02-09; source msha-controller-operator-history
- **operator_operates_mine:** South Fork Coal Co., LLC → Blue Knob Surface Mine; 2012-03-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Xinergy Ltd → South Fork Coal Co., LLC; 2012-03-02 to 2016-02-09; source msha-controller-operator-history
- **controller_controls_mine:** White Forest Resources, Inc → Blue Knob Surface Mine; 2016-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** White Forest Resources, Inc → South Fork Coal Co., LLC; 2016-02-10 to current/open; source msha-controller-operator-history