# Relationship history for MSHA mine 3402117

Current hierarchy: **Micheal K.  Matthews; Justin L.  Muggenborg → Dover Sand Plant LLC → Dover Sand Plant LLC**

- 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

- **operator_operates_mine:** Dover Sand Plant LLC → Dover Sand Plant LLC; 2011-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Justin L.  Muggenborg et al → Dover Sand Plant LLC; 2011-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Justin L.  Muggenborg et al → Dover Sand Plant LLC; 2011-08-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Micheal K.  Matthews et al → Dover Sand Plant LLC; 2011-08-15 to current/open; source msha-controller-operator-history