United States Government--gayville, Post Office 508 Washington Wakonda, SD 57073 Phone : (605) 267-4389 Business Category Government Offices-Federal Post Offices Government Offices & Public Schools Post Office - Gayville 508 Washington St Gayville, SD 57031 Phone : (605) 267-4389 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (605) 357-4906 United States Postal Service , Phone : (605) 267-4389 United States Postal Service Business Category