There are 22 US Post Offices in Berrien County serving a total of 198,669 residents equating to 9,030 residents per post office. It's estimated that approximately 317,098 packages are handled across the 22 county post offices annually. Berrien County is a county located in southwest Michigan just north of Indiana. As of the 2010 census, the population is 156,813. The county seat is St. Joseph. Berrien County is included in the Niles-Benton Harbor, MI Metropolitan Statistical Area, which is also included in the South Bend-Elkhart-Mishawaka, IN-MI Combined Statistical Area."