There are 8 US Post Offices in Calumet County serving a total of 25,443 residents equating to 3,180 residents per post office. It's estimated that approximately 40,610 packages are handled across the 8 county post offices annually. Calumet County is a county located in the U.S. state of Wisconsin. As of the 2010 census, the population was 48,971. The county seat is Chilton. The county was created in 1836 (then in the Wisconsin Territory) and organized in 1850. Calumet County is included in the Appleton, WI Metropolitan Statistical Area as well as the Appleton-Oshkosh-Neenah, WI Combined Statistical Area. The Holyland is partially located in southern Calumet County."