There are 7 US Post Offices in Hutchinson County serving a total of 7,168 residents equating to 1,024 residents per post office. It's estimated that approximately 11,441 packages are handled across the 7 county post offices annually. Hutchinson County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 7,343. Its county seat is Olivet. The county was created in 1862 and organized in 1871. It was named for John Hutchinson, first territorial secretary."