There are 5 US Post Offices in Cottonwood County serving a total of 11,037 residents equating to 2,207 residents per post office. It's estimated that approximately 17,616 packages are handled across the 5 county post offices annually. Cottonwood County is a county located in the U.S. state of Minnesota. As of the 2010 census, the population was 11,687. Its county seat is Windom. The county was formed in 1857 and organized in 1870."