There are 11 US Post Offices in Collier County serving a total of 166,399 residents equating to 15,127 residents per post office. It's estimated that approximately 265,591 packages are handled across the 11 county post offices annually. Collier County is a county located in the U.S. state of Florida. As of the 2010 census, the population was 321,520. Its county seat is East Naples, where the county offices were moved from Everglades in 1962. Collier County comprises the Naples-Immokalee-Marco Island, FL Metropolitan Statistical Area, which is included in the Cape Coral-Fort Myers-Naples, FL Combined Statistical Area."