# Relationship history for MSHA mine 4104855

Current hierarchy: **USS Holdings Inc → U. S. Silica Company → US Silica-Voca Plant**

- 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:** USS Holdings Inc → US Silica-Voca Plant; 1996-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cadre Material Products, LLC → US Silica-Voca Plant; 2011-02-17 to 2019-05-16; source msha-controller-operator-history
- **controller_controls_mine:** Kimberly  Bowron et al → US Silica-Voca Plant; 2011-02-17 to 2014-07-30; source msha-controller-operator-history
- **controller_controls_operator:** Kimberly  Bowron et al → Cadre Material Products, LLC; 2011-02-17 to 2014-07-30; source msha-controller-operator-history
- **controller_controls_mine:** USS Holdings Inc → US Silica-Voca Plant; 2014-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USS Holdings Inc → Cadre Material Products, LLC; 2014-07-31 to 2019-05-16; source msha-controller-operator-history
- **operator_operates_mine:** U. S. Silica Company → US Silica-Voca Plant; 2019-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USS Holdings Inc → U. S. Silica Company; 2019-05-17 to current/open; source msha-controller-operator-history