# Relationship history for MSHA mine 4703091

Current hierarchy: **Thomas W  Hensel → T & T Stone Co. Inc. → T & T Stone Co. Inc. Stan Lien Quarry**

- 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:** T & T Stone Co. Inc. → T & T Stone Co. Inc. Stan Lien Quarry; 1996-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas W  Hensel → T & T Stone Co. Inc. Stan Lien Quarry; 1996-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas W  Hensel → T & T Stone Co. Inc.; 1996-11-01 to current/open; source msha-controller-operator-history