There are 11 US Post Offices in Boone County serving a total of 196,825 residents equating to 17,893 residents per post office. It's estimated that approximately 314,155 packages are handled across the 11 county post offices annually. Boone County is a county located in the U.S. state of Missouri. As of the 2010 census, the population was 162,642; a 2015 estimate put the population at 174,974, making it the seventh-most populous county in the state. Its county seat is Columbia, the fourth-largest city in Missouri. The county was organized November 16, 1820 and named for Daniel Boone. Boone County comprises the Columbia, MO Metropolitan Statistical Area. The University of Missouri is located in Columbia.