There are 9 US Post Offices in Douglas County serving a total of 43,648 residents equating to 4,850 residents per post office. It's estimated that approximately 69,667 packages are handled across the 9 county post offices annually. Douglas County is a county located at the northwest corner of the U.S. state of Wisconsin. As of the 2010 census, the population was 44,159. Its county seat is Superior. Douglas County is included in the Duluth, MN-WI Metropolitan Statistical Area."