There are 11 US Post Offices in Muskegon County serving a total of 96,268 residents equating to 8,752 residents per post office. It's estimated that approximately 153,654 packages are handled across the 11 county post offices annually. Muskegon County is a county located in the U.S. state of Michigan. As of 2014, the population was 172,344. The county seat is Muskegon. Muskegon County comprises the Muskegon, MI Metropolitan Statistical Area, which is part of the larger Grand Rapids-Wyoming-Muskegon, MI Combined Statistical Area. The White River flows through the county to its mouth at Lake Michigan."