# Relationship history for MSHA mine 3609230

Current hierarchy: **Joseph K  Zawisky → Joseph Zawisky LLC → Clapper Quarry #2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Tammy L  Norton → Clapper Quarry #2; 2003-01-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tammy & Norm Norton (Norm Norton Stone) → Clapper Quarry #2; 2004-04-12 to 2005-03-22; source msha-controller-operator-history
- **controller_controls_operator:** Tammy L  Norton → Tammy & Norm Norton (Norm Norton Stone); 2004-04-12 to 2005-03-22; source msha-controller-operator-history
- **operator_operates_mine:** Joseph Zawisky LLC → Clapper Quarry #2; 2005-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joseph K  Zawisky → Clapper Quarry #2; 2005-03-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph K  Zawisky → Joseph Zawisky LLC; 2005-03-23 to current/open; source msha-controller-operator-history