There are 8 US Post Offices in Ritchie County serving a total of 10,998 residents equating to 1,375 residents per post office. It's estimated that approximately 17,554 packages are handled across the 8 county post offices annually. Ritchie County is a county in the U.S. state of West Virginia. As of the 2010 census, the population was 10,449. Its county seat is Harrisville. The county was created in 1843 by the Virginia General Assembly and named for Richmond newspaper publisher Thomas Ritchie."