There are 6 US Post Offices in Chariton County serving a total of 6,516 residents equating to 1,086 residents per post office. It's estimated that approximately 10,400 packages are handled across the 6 county post offices annually. Chariton County is a county located in the North Central portion of the U.S. state of Missouri. As of the 2010 census, the population was 7,831. Its county seat is Keytesville. The county was organized November 16, 1820, from part of Howard County and is named for the Chariton River."