Aspen Center for Environmental Studies

A nonprofit organization

Aspen Center for Environmental Studies (ACES) is a non-profit environmental science education organization. We forge bold innovation in environmental science education, sustainable agriculture, and forest health and ecosystem restoration.

Aspen Center for Environmental Studies (ACES) is a nonprofit environmental science education organization with three locations in the Roaring Fork Valley: Hallam Lake, Rock Bottom Ranch, and the Catto Center at Toklat. Our mission is to “educate for environmental responsibility” by building ecological literacy and creating a community of knowledgeable and motivated environmental stewards. ACES’ work focuses on the areas of ecological literacy, regenerative agriculture, forest health, and ecosystem restoration, and connecting people to nature. 


Educating for Environmental Responsibility

Background Statement

In 1969, Elizabeth Paepcke donated her 25-acre property in the West End of Aspen for the development of an environmental center and preserve. She was motivated by "The Aspen Idea" of harmony between mind, body, and spirit, and envisioned a place that would provide a bridge to nature for an increasingly urbanized society, while also serving as a sanctuary for wildlife in the heart of Aspen. As a child, Elizabeth had also been influenced by her experiences with Enos Mills, the father of Rocky Mountain National Park.

Elizabeth Paepcke was joined in her efforts by a number of founding trustees, notably science teacher Bob Lewis and botanist Stuart Mace. Together, they hoped that the nature center would provide programs in ecology and natural sciences for everyone, from school children to leaders and decision-makers.

Since then, ACES has expanded its environmental education reach to schools from Aspen to Rifle, partnering with more than 60 schools to provide education programs in the classroom and field. In addition to science education, ACES also focuses on sustainable food systems and regenerative agriculture, forest health, habitat restoration, and connecting adults and children to nature. In the next 50 years, we will continue to build a community of ecologically literate citizens, aiming to be a beacon of science-based environmental leadership and education for all ages, creating a deeper connection between humans and the natural world.

Organization Data


Organization name

Aspen Center for Environmental Studies

other names


Year Established


Tax id (EIN)




Organization Size

Large Organization


100 Puppy Smith Street
Aspen, CO 81611


2001 Hooks Spur Road
Basalt, CO 81621


11247 Castle Creek Road
Aspen, CO 81611

Service areas

Pitkin County, CO, US

Eagle County, CO, US





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