There are 10 US Post Offices in Crawford County serving a total of 16,639 residents equating to 1,664 residents per post office. It's estimated that approximately 26,558 packages are handled across the 10 county post offices annually. Crawford County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 17,096. Its county seat is Denison. The county was named for William Harris Crawford, U.S. senator from Georgia and United States Secretary of the Treasury."