# Relationship history for MSHA mine 3609429

Current hierarchy: **Timothy M  Smith → B S Quarries Inc → Rock Lake 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

- **controller_controls_mine:** Timothy M  Smith → Rock Lake Quarry; 1997-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kevin  Schrader → Rock Lake Quarry; 2005-08-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Como Stone → Rock Lake Quarry; 2006-05-10 to 2007-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Kevin  Schrader → Como Stone; 2006-05-10 to 2007-10-31; source msha-controller-operator-history
- **operator_operates_mine:** B S Quarries Inc → Rock Lake Quarry; 2007-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timothy M  Smith → B S Quarries Inc; 2007-11-01 to current/open; source msha-controller-operator-history