# Relationship history for MSHA mine 3003428

Current hierarchy: **James A  Alvarez; Thomas A  Alvarez → John A. Alvarez & Sons, Inc. → John A. Alvarez & Sons Sand & Gravel**

- 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:** John A. Alvarez & Sons, Inc. → John A. Alvarez & Sons Sand & Gravel; 2002-08-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tom A  Alvarez  et al → John A. Alvarez & Sons Sand & Gravel; 2002-08-14 to 2016-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Tom A  Alvarez  et al → John A. Alvarez & Sons, Inc.; 2002-08-14 to 2016-08-09; source msha-controller-operator-history
- **controller_controls_operator:** John D  Alvarez  et al → John A. Alvarez & Sons, Inc.; 2002-08-14 to 2016-08-09; source msha-controller-operator-history
- **controller_controls_operator:** James M  Alvarez  et al → John A. Alvarez & Sons, Inc.; 2002-08-14 to 2016-08-09; source msha-controller-operator-history
- **controller_controls_mine:** Thomas A  Alvarez et al → John A. Alvarez & Sons Sand & Gravel; 2016-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas A  Alvarez et al → John A. Alvarez & Sons, Inc.; 2016-08-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James A  Alvarez et al → John A. Alvarez & Sons, Inc.; 2016-08-10 to current/open; source msha-controller-operator-history