There are 8 US Post Offices in Harrison County serving a total of 14,721 residents equating to 1,840 residents per post office. It's estimated that approximately 23,496 packages are handled across the 8 county post offices annually. Harrison County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 14,928. The county seat is Logan. The county was formed in 1851. It was named for ninth US President William H. Harrison. Harrison County is included in the Omaha-Council Bluffs, NE-IA Metropolitan Statistical Area."