Dewey County Post Offices

121 Main St
Eagle Butte, South Dakota 57625

200 Main St
Isabel, South Dakota 57633

1 N Highway 212
Lantry, South Dakota 57636

1 Highway 212
Ridgeview, South Dakota 57652

801 Main St
Timber Lake, South Dakota 57656

130 N Main St
Trail City, South Dakota 57657

500 Main St
Whitehorse, South Dakota 57661

Dewey County

There are 7 US Post Offices in Dewey County serving a total of 6,224 residents equating to 889 residents per post office. It's estimated that approximately 9,934 packages are handled across the 7 county post offices annually. Dewey County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 5,301. Its county seat is Timber Lake. The county was created in 1883 and organized in 1910. It was named for William P. Dewey, Territorial surveyor-general from 1873 to 1877. Almost the entire county lies in the Cheyenne River Indian Reservation. The balance of the county, along its extreme northern county line, lies in the Standing Rock Indian Reservation. It is one of five South Dakota counties that are contained within Indian reservations."