# Relationship history for MSHA mine 3609983

Current hierarchy: **Michael D  Austin → Austin Sand and Gravel → Windham 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** John  Insinger → Windham Quarry; 2009-05-15 to 2024-02-07; source msha-controller-operator-history
- **operator_operates_mine:** Insinger Excavating → Windham Quarry; 2011-12-27 to 2022-03-08; source msha-controller-operator-history
- **controller_controls_operator:** John  Insinger → Insinger Excavating; 2011-12-27 to 2022-03-08; source msha-controller-operator-history
- **controller_controls_mine:** Michael D  Austin → Windham Quarry; 2014-10-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Austin Sand and Gravel → Windham Quarry; 2022-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael D  Austin → Austin Sand and Gravel; 2022-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Christopher J Insinger → Windham Quarry; 2024-02-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Christopher J Insinger → Insinger Excavating; 2024-02-08 to 2022-03-08; source msha-controller-operator-history