There are 11 US Post Offices in Manistee County serving a total of 38,850 residents equating to 3,532 residents per post office. It's estimated that approximately 62,009 packages are handled across the 11 county post offices annually. Manistee County is a county located in the U.S. state of Michigan. As of the 2010 census, the population was 24,733. The county seat is Manistee. The name \"Manistee\" is from an Ojibwe word first applied to the principal river of the county. The derivation is not certain, but it may be from ministigweyaa, \"river with islands at its mouth\". See also, List of Michigan county name etymologies and Kaministiquia River."