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 is Fairplay. 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.