There are 4 US Post Offices in Chaffee County serving a total of 17,891 residents equating to 4,473 residents per post office. It's estimated that approximately 28,556 packages are handled across the 4 county post offices annually. Chaffee County is one of the 64 counties of the U.S. state of Colorado. As of the 2010 census, the population was 17,809. The county seat is Salida."