There are 2 Post Offices in Sully County, South Dakota, serving a population of 1,390 people in an area of 1,007 square miles. There is 1 Post Office per 695 people, and 1 Post Office per 503 square miles.
In South Dakota, Sully County is ranked 16th of 66 counties in Post Offices per capita, and 61st of 66 counties in Post Offices per square mile.
Find addresses, phone numbers, fax numbers, hours & services for Sully County Post Offices.
United States Postal Service 206 Ash Street Agar, SD Mailing Service, Postal Services
United States Postal Service 703 Birch Avenue Onida, SD Mailing Service, Postal Services