# Relationship history for MSHA mine 4502571

Current hierarchy: **Okanogan County-Wa → Okanogan County Road Department-Wa → Winthrop Shop Pit**

- 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:** Knapp Kenneth K → Winthrop Shop Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Okanogan County-Wa → Winthrop Shop Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Okanogan County Road Department-Wa → Winthrop Shop Pit; 1978-03-09 to 1978-09-12; source msha-controller-operator-history
- **controller_controls_operator:** Okanogan County-Wa → Okanogan County Road Department-Wa; 1978-03-09 to 1978-09-12; source msha-controller-operator-history
- **operator_operates_mine:** Northwest Paving & Construction Company Inc → Winthrop Shop Pit; 1978-09-13 to 1979-07-23; source msha-controller-operator-history
- **controller_controls_operator:** Knapp Kenneth K → Northwest Paving & Construction Company Inc; 1978-09-13 to 1979-07-23; source msha-controller-operator-history
- **operator_operates_mine:** Okanogan County Road Department-Wa → Winthrop Shop Pit; 1979-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Okanogan County-Wa → Okanogan County Road Department-Wa; 1979-07-24 to current/open; source msha-controller-operator-history