Union County is in Southeast South Dakota. Of the 66 counties in the Coyote State, 467-square-mile Union County ranks 62nd by size. There is 1,000 acres of farms for sale in South Dakota's Union County based on recent Land Network data. The combined market value of farms and ranches for sale here is $5 million. The average price of farmland for sale in Union County was $1 million. Farms for sale in Union County feature livestock including cattle, horses, goats and sheep. Browse all South Dakota farms for sale on the Land Network to find the farm, cattle operation, hobby farm or other farm property that's right for your future business or lifestyle needs.