There are 3 US Post Offices in Geary County serving a total of 42,686 residents equating to 14,229 residents per post office. It's estimated that approximately 68,132 packages are handled across the 3 county post offices annually. Geary County (county code GE) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 34,362. Its county seat and most populous city is Junction City. The county is named in honor of Governor John W. Geary."