There are 8 US Post Offices in Pottawatomie County serving a total of 18,876 residents equating to 2,360 residents per post office. It's estimated that approximately 30,128 packages are handled across the 8 county post offices annually. Pottawatomie County (standard abbreviation: PT) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 21,604. The county seat is Westmoreland. The county takes its name from the Potawatomi tribe of Native Americans."