# Relationship history for MSHA mine 4407378

Current hierarchy: **Thomas  Blair; Richard  Blair; Nora  Johnson → Blair Sand & Materials, LLC → Three Creek 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Matt  Crowder → Three Creek Mine; 2015-03-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Crowder and White Contracting, LLC → Three Creek Mine; 2017-08-01 to 2018-03-07; source msha-controller-operator-history
- **controller_controls_operator:** Matt  Crowder → Crowder and White Contracting, LLC; 2017-08-01 to 2018-03-07; source msha-controller-operator-history
- **operator_operates_mine:** Blair Sand & Materials, LLC → Three Creek Mine; 2018-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Blair et al → Three Creek Mine; 2018-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Blair et al → Blair Sand & Materials, LLC; 2018-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nora  Johnson et al → Blair Sand & Materials, LLC; 2018-03-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  Blair et al → Blair Sand & Materials, LLC; 2018-03-08 to current/open; source msha-controller-operator-history