Park County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 17,390. The county seat and largest incorporated town is Fairplay, while the unincorporated community of Bailey is the largest settlement overall. The county was named after the large geographic region known as South Park, which was named by …Park County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 17,390. The county seat and largest incorporated town is Fairplay, while the unincorporated community of Bailey is the largest settlement overall. The county was named after the large geographic region known as South Park, which was named by early fur traders and trappers in the area. Park County is included in the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area. A majority of the county lies within the boundaries of the South Park National Heritage Area.