South Park is a high intermontane grassland basin, approximately 10,000 ft (3,000 m) in elevation, in the Rocky Mountains of central Colorado. It encompasses approximately 1,000 square miles (2789 km² or 640,000 acres) around the headwaters of the South Platte River in Park County approximately 60 mi (100 km) southwest of Denver. It is the southernmost of three such large mountain valleys in Colorado, along with North Park and Middle Park.