There are 5 US Post Offices in Benton County serving a total of 18,928 residents equating to 3,786 residents per post office. It's estimated that approximately 30,211 packages are handled across the 5 county post offices annually. Benton County is a county located in the west central part of the U.S. state of Missouri. The population was 19,056 as of the 2010 Census. Its county seat is Warsaw. The county was organized January 3, 1835, and named for U.S. Senator Thomas Hart Benton of Missouri."