# Relationship history for MSHA mine 4702783

Current hierarchy: **Jeffery A  Gaastra → Sam Gaastra & Sons Inc → Washara Co Operations**

- 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:** Sam  Gaastra → Washara Co Operations; 1980-07-01 to 2021-05-23; source msha-controller-operator-history
- **operator_operates_mine:** Sam Gaastra & Sons Inc → Washara Co Operations; 1985-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam  Gaastra → Sam Gaastra & Sons Inc; 1985-05-01 to 2021-05-23; source msha-controller-operator-history
- **controller_controls_mine:** Jeffery A  Gaastra → Washara Co Operations; 2021-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeffery A  Gaastra → Sam Gaastra & Sons Inc; 2021-05-24 to current/open; source msha-controller-operator-history