# Relationship history for MSHA mine 1518290

Current hierarchy: **Glenn M  Salyer → River Sand & Gravel, LLC → River Sand & Gravel, 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Lewis County Sand & Gravel Inc → River Sand & Gravel, LLC; 2000-10-01 to 2005-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Carey  Highfield → River Sand & Gravel, LLC; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carey  Highfield → Lewis County Sand & Gravel Inc; 2000-10-01 to 2005-12-04; source msha-controller-operator-history
- **operator_operates_mine:** River Sand & Gravel, LLC → River Sand & Gravel, LLC; 2005-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Red River Ranch LLC et al → River Sand & Gravel, LLC; 2005-12-05 to 2012-09-29; source msha-controller-operator-history
- **controller_controls_operator:** Red River Ranch LLC et al → River Sand & Gravel, LLC; 2005-12-05 to 2012-09-29; source msha-controller-operator-history
- **controller_controls_operator:** Walker Ventures LLC et al → River Sand & Gravel, LLC; 2005-12-05 to 2012-09-29; source msha-controller-operator-history
- **controller_controls_mine:** Glenn M  Salyer → River Sand & Gravel, LLC; 2012-09-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Glenn M  Salyer → River Sand & Gravel, LLC; 2012-09-30 to current/open; source msha-controller-operator-history