what is the zip code for keystone co
Keystone is a census-designated place (CDP) in Summit County, Colorado, United States. The population was 1,079 at the 2010 census. The Dillon Post Office (ZIP Code 80435) serves Keystone postal addresses. Keystone is the home of the Keystone Resort. Originally constructed in the 1970s by the Ralston Purina Company, it is now owned by Vail Resorts. The Keystone Resort ski area occupies 3 separate mountains: Dercum Mountain, North Peak, and The Outback.