# Relationship history for MSHA mine 4104377

Current hierarchy: **Ray  Thornbrue → Sand & Gravel, Inc. → Sand & Gravel, INc.**

- 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:** Sand & Gravel, Inc. → Sand & Gravel, INc.; 2002-07-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ray  Thornbrue → Sand & Gravel, INc.; 2002-07-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ray  Thornbrue → Sand & Gravel, Inc.; 2002-07-18 to current/open; source msha-controller-operator-history