In the next 50 years, ACES will be a beacon of science-based environmental leadership and education for all ages and cultures, creating a deeper connection between humans and the natural world. Our sites will be world-class hubs of science education.

Hallam Lake


Loved and appreciated by visitors and locals, ACES’ 50th anniversary capital campaign will allow us to restore and improve riparian and aquatic habitat within our Hallam Lake nature preserve.

Hallam Lake is the heart and hub of ACES programming in the Aspen community, where children, families, and adults come to develop curiosity and connection to the natural world.

Hallam Lake focuses on environmental education for all ages in our natural preserve and headquarters building with little human disturbance adjacent to the center of Aspen. This unique setting provides visitors easy access to experience and learn from the wild. It has a tranquil space for visitors to observe, learn, and contemplate sacred nature and our role within it.

By renovating the Hallam Lake visitor center, we will improve the visitor experience and education through this site.

Access to the visitor center lab and south patio will be opened up from the reception area. In addition, the back deck will be altered to blend in better with the surrounding preserve. The nearby eagle mound will also wrap around to connect with the south patio. These structural improvements will provide a better visitor experience, allow for improved mobility, and enhance events.

A 5-acre wetland restoration project and a new building at our spring-fed Hallam Lake, will help to maintain the ecological balance of the site.

We will create diverse aquatic habitat and reintroduce native species. The lake’s leaky levee and old malfunctioning outflow structures need to be repaired. Overabundant cattails have compromised some of the habitat in and around the lake. ACES will work with Colorado Parks & Wildlife to restore the cutthroat trout population. All these projects will benefit nature and visitors to Hallam Lake.

Rock Bottom Ranch


At Rock Bottom Ranch, ACES is demonstrating the power we can harness through our food systems to create a better future.

Increasing global carbon emissions is, perhaps, the most significant environmental challenge facing our world today. While conventional agricultural practices continue to be one of the primary contributors to global carbon emissions, the solution to these challenges can also be found in agriculture.

At Rock Bottom Ranch, ACES is modeling a regenerative agriculture system that reduces carbon emissions and increases carbon sequestration. We are creating jobs and invigorating our local communities. Representing an economically-profitable business model, we hope to share this approach with the public.

In order to serve as a model in the field, ACES will invest in infrastructure to demonstrate scalable, replicable systems of regenerative agriculture.

We recognize the the potential of this place that is favorable to both traditional vegetable production systems and livestock.

Using our multi-species rotational grazing system, we are increasing ecological health and agricultural productivity.

Catto Center at Toklat


As a gift to our community, our goal with ACES’ capital campaign in 2019 is to renovate and reopen the Catto Center at Toklat.

The Catto Center at Toklat, an iconic wilderness retreat center, embodies ACES’ environmental ethic and spirit of stewardship.

A complete Catto Center renovation as a deep ecology retreat center for our community will include:

  • ACES Naturalist housing,
  • Artist-in-residence space,
  • Caretaker unit,
  • New interior,
  • Code compliance, and more. 

Nestled high in the pristine Castle Creek Valley, the site is often compared to Thoreau’s Walden Pond, Leopold’s Shack, or the Murie Ranch. The Catto Center at Toklat provides a unique “window into wilderness” for visitors to experience the extraordinary beauty and to understand the rich ecological diversity of the upper Castle Creek Valley. The goal is to challenge the visitor to explore the scientific, historical, and spiritual roots of our relationship with the natural world.

Renderings provided by Stan Clauson Associates, planning and landscape design consultants for the project.

As we envision the future of this unique site, we are focused on creating a space defined by nature & beauty that will benefit scores of people.

ACES is working with renowned architect and design firms, Stan Clauson Associates and Michael Fuller Architects, to lead the renovation of the Catto Center at Toklat.

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Hallam Lake

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Catto Center at Toklat