# Relationship history for MSHA mine 4105019

Current hierarchy: **Anthony S Ridout → 16 Sand, LLC → 16 Sand, 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:** South Texas Sand LLC → 16 Sand, LLC; 2013-06-19 to 2014-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Walker M.  Schmidt → 16 Sand, LLC; 2013-06-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walker M.  Schmidt → South Texas Sand LLC; 2013-06-19 to 2014-10-15; source msha-controller-operator-history
- **operator_operates_mine:** 16 Sand, LLC → 16 Sand, LLC; 2014-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Anthony S Ridout → 16 Sand, LLC; 2014-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Anthony S Ridout → 16 Sand, LLC; 2014-10-16 to current/open; source msha-controller-operator-history