There are 7 US Post Offices in Harvey County serving a total of 36,373 residents equating to 5,196 residents per post office. It's estimated that approximately 58,055 packages are handled across the 7 county post offices annually. Harvey County (county code HV) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 34,684. Its county seat and most populous city is Newton."