# Relationship history for MSHA mine 4502327

Current hierarchy: **State Of Washington → Washington State Park & Recreation Commission → Bucks Gravel 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Bucks Gravel → Bucks Gravel Pit; 1950-01-01 to 1980-04-15; source msha-controller-operator-history
- **controller_controls_mine:** Buchmann Donald F & Grace E → Bucks Gravel Pit; 1950-01-01 to 1980-04-15; source msha-controller-operator-history
- **controller_controls_operator:** Buchmann Donald F & Grace E → Bucks Gravel; 1950-01-01 to 1980-04-15; source msha-controller-operator-history
- **operator_operates_mine:** Washington State Park & Recreation Commission → Bucks Gravel Pit; 1980-04-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** State Of Washington → Bucks Gravel Pit; 1980-04-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** State Of Washington → Washington State Park & Recreation Commission; 1980-04-16 to current/open; source msha-controller-operator-history