United States Government--postal Service, Wauconda 2432 E Highway 20 Tonasket, WA 98855 Phone : (509) 486-4566 Business Category Government Offices-Federal Government Offices & Public Schools Post Office - Wauconda 2360 Highway 20 Wauconda, WA 98859 Phone : (509) 486-4566 Business Category Post Offices Toll-Free           (800) ASK-USPS