There are 5 US Post Offices in Wadena County serving a total of 21,175 residents equating to 4,235 residents per post office. It's estimated that approximately 33,798 packages are handled across the 5 county post offices annually. Wadena County (/w\u0259\u02c8di\u02d0n\u0259/ w\u0259-DEEN-\u0259) is a county located in the U.S. state of Minnesota. As of the 2010 census, the population was 13,843. Its county seat is Wadena. The county was formed in 1858 and organized in 1873."