# Relationship history for MSHA mine 3609276

Current hierarchy: **William E  Corson → Contract Crushing/Construction Inc → Portable Crushing Plant-Operation No 1**

- 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:** Contract Crushing/Construction Inc → Portable Crushing Plant-Operation No 1; 2004-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William E  Corson → Portable Crushing Plant-Operation No 1; 2004-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William E  Corson → Contract Crushing/Construction Inc; 2004-08-24 to current/open; source msha-controller-operator-history