Hallam Lake, a 25-acre nature preserve and environmental learning center, was the first location of the Aspen Center for Environmental Studies. The Hallam Lake property was donated in 1968 by Elizabeth Paepcke. The preserve is open to the public year-round and provides an inspiring...

Rock Bottom Ranch serves as ACES' mid-valley hub for environmental education, wildlands preservation, and sustainable agriculture. The 113-acre wildlife preserve and educational Ranch sits between the Roaring Fork River and the Crown of Mount Sopris and is conveniently located…

The Catto Center at Toklat was once the family home of one of ACES’ most influential founders, Stuart Mace, and holds great meaning for the Aspen community. Toklat, an Inuit word meaning “headwaters,” was built by Stuart and and his wife Isabel in 1948 as a wilderness lodge and family...