Union County Post Offices

111 Dakota St
Alcester, South Dakota 57001

100 S 3rd St
Beresford, South Dakota 57004

123 W Main St
Elk Point, South Dakota 57025

303 Main St
Jefferson, South Dakota 57038

310 N Derby Ln
North Sioux City, South Dakota 57049

Union County

There are 5 US Post Offices in Union County serving a total of 15,279 residents equating to 3,056 residents per post office. It's estimated that approximately 24,387 packages are handled across the 5 county post offices annually. Union County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 14,399. Its county seat is Elk Point. Originally named Cole County, the named was changed to Union because of Civil War sentiment. Union County is part of the Sioux City, IA\u2013NE\u2013SD Metropolitan Statistical Area. Progressive Farmer rated Union County second in the 2006 \"Best Place to Live\" in the U.S., because \"its schools are good, its towns neat and its people friendly.\""