There are 4 US Post Offices in Pratt County serving a total of 9,150 residents equating to 2,288 residents per post office. It's estimated that approximately 14,604 packages are handled across the 4 county post offices annually. Pratt County (standard abbreviation: PR) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 9,656. The largest city and county seat is Pratt."