| | Benton County | WA | 53005 | | Kennewick-Richland, WA 28420 | Kennewick-Richland-Walla
Walla, WA 314 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=BentonCounty+WA |
| | Franklin County | WA | 53021 | | Kennewick-Richland, WA 28420 | Kennewick-Richland-Walla
Walla, WA 314 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=FranklinCounty+WA |
| | Walla Walla County | WA | 53071 | | Walla Walla, WA 47460 | Kennewick-Richland-Walla
Walla, WA 314 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=WallaWallaCounty+WA |