botanical garden - a facility where trees and shrubs are cultivated for exhibition. arboretum. facility, installation - a building or place that provides a particular service or is used for a particular industry; the assembly plant is an enormous facility.
Keystone, CO Weather. The average temperature of Keystone is 35.80Â°F, which is much lower than the Colorado average temperature of 46.26Â°F and is much lower than the national average temperature of 54.45Â°F. Historical Weather.
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.