# Relationship history for MSHA mine 3600684

Current hierarchy: **Wienerberger AG → Watsontown Brick Company → THE WATSONTOWN BRICK CO. 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:** Watsontown Brick Company → THE WATSONTOWN BRICK CO. QUARRY; 1950-01-01 to 2021-02-09; source msha-controller-operator-history
- **controller_controls_mine:** Michael P  Fisher → THE WATSONTOWN BRICK CO. QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael P  Fisher → Watsontown Brick Company; 1950-01-01 to 2021-02-09; source msha-controller-operator-history
- **controller_controls_mine:** Wienerberger AG → THE WATSONTOWN BRICK CO. QUARRY; 2002-07-19 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Watsontown Brick Company → THE WATSONTOWN BRICK CO. QUARRY; 2021-02-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wienerberger AG → Watsontown Brick Company; 2021-02-10 to current/open; source msha-controller-operator-history