# Relationship history for MSHA mine 3609908

Current hierarchy: **Gary L  Thompson → Parker Sand and Gravel Company → Finlay Power Screen**

- 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:** Gary L  Thompson → Finlay Power Screen; 1986-04-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Parker Sand and Gravel Company → Finlay Power Screen; 2011-03-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary L  Thompson → Parker Sand and Gravel Company; 2011-03-02 to current/open; source msha-controller-operator-history