Jefferson is an unincorporated community in Park County, Colorado, United States. Description The community is located in the northern end of South Park, along U.S. Route 285 (US 285), approximately northeast of Fairplay, at the western foot of Kenosha Pass. t lies from Como, from Bailey, and from Breckenridge. The community consists largely of a strip of retail businesses along US 285, as well as a small unpaved grid of houses and trailers on the south side of the highway. The most notable landmarks in the community are a historic one-room schoolhouse and the Historic Jefferson Denver, South Park and Pacific Railroad (DSP&P RR)Depot (c. 1880), highly visible in the surrounding grasslands of South Park. The Jefferson Post Office has the ZIP Code 80456. However, the post office closed in 2022. Geography Jefferson is located at (39.568,-105.801). See also References External links Unincorporated communities in Park County, Colorado Unincorporated communities in Colorado