There are 14 US Post Offices in Clark County serving a total of 32,721 residents equating to 2,337 residents per post office. It's estimated that approximately 52,226 packages are handled across the 14 county post offices annually. Clark County is a county located in the U.S. state of Wisconsin. As of the 2010 census, the population was 34,690. Its county seat is Neillsville."