# Relationship history for MSHA mine 4202686

Current hierarchy: **William  Leavitt; Greg Kent  Dippold → North Slope Crushing, LLC → Portable 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:** William  Leavitt et al → Portable 2; 2015-11-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** North Slope Crushing, LLC → Portable 2; 2018-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Leavitt et al → North Slope Crushing, LLC; 2018-02-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greg Kent  Dippold et al → North Slope Crushing, LLC; 2018-02-15 to current/open; source msha-controller-operator-history