Hallam Lake


9AM - 5PM Monday-Friday.
9AM - 5PM Saturdays in summer.


100 Puppy Smith St., Aspen, CO 81611


Please email Grayson Bauer at [email protected] to inquire about rentals.


NOTICE: Hallam Lake Nature Preserve is undergoing a restoration. Due to this project, some of our trails may be closed. 

Our Nature Center is open, and you can still come visit the indoor animals, trout stream, gift shop, and chat with our naturalists! We will also be open for programs, including Morning Birding.

You can read more about the Hallam Lake Restoration project as a whole here, and updates to the project will be listed here.

*If you are interested in bringing a group of students to visit Hallam Lake during the summer, please call us at (970) 925-5756 to make sure we can accommodate a visit for your group. There is a suggested donation of $1 per child.



About Hallam Lake

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 setting for ACES’ many educational and naturalist programs. Borrow our binoculars and search for local wildlife. Keep your eyes out for freely roaming mule deer, elk, foxes, coyotes, bear, beavers, golden eagles, hawks, songbirds, and more!

Directions: We are located at the end of Puppy Smith Street behind the Aspen Post Office. You will reach a set of stone gates. The parking lot is on the left, and then you can walk down through the gates on the trail to the Hallam Lake Nature Center, which will be at the end of the trail on the left. Please call 970-925-5756 if you are lost!



Hallam Lake Activies


Some of our activites are currently limited. Check back soon for updates when the following activities are back in action!

Visit the Indoor Animals

Visit ACES' Lab to check out our indoor animals, including a bearded dragon, ball python, salamander, and cockroaches. On-site Naturalists are available to introduce you and your family to these special creatures!

Observe the Trout Stream

Experience close-up views of native Colorado cutthroat trout, Oncorhynchus clarki pleuriticus. A sample of these native trout was taken from a relic population living in Lake Nanita in Rocky Mountain National Park by the Colorado Division of Wildlife and stocked in Hallam Lake. It is this group of beautiful golden-brown, black-spotted trout with the bright orange slash on the lower jaw that we see in the indoor trout stream. The cutthroat trout in the stream are fed crickets, flies, scuds, and other live food.

Wander the Garden

Spring through fall, enjoy ACES' organic garden, a teaching space where visitors can learn about flowering, pollination, and local food. You can walk on the labyrinth and identify a combination of native plants, traditional herbs, and cultivated species.

Explore the Nature Preserve (currently unavailable)

A half-mile loop nature trail is available for all visitors, and meanders in and out of wetlands and includes stops at various observation decks. Use our self-guided tour book to learn about our local landscape, or adventure on your own, experiencing aspen forest, wetlands, and meadows. An on-site Naturalist is always available to answer any questions you may have. Summertime offers a bounty of wildflowers, while winter is an excellent time to learn animal tracks!

Spot Local Wildlife (currently unavailable)

On any given day, a variety of birds and mammals can be seen feeding at the water's edge. During the day, swallows perform acrobatics above the water in search of insects, while the American dipper dives underwater in search of aquatic insects. As the sun sets, fox, bear, and deer prowl the banks searching for dinner, while beaver cautiously feed on willow, aspen, and cottonwood bark around the lake. Hallam Lake is home to resident birds of prey and lush riparian ecosystems including woodland, meadow, pond, and marsh communities.

Meet the Raptors (currently unavailable)

Meet ACES' resident Great Horned Owl and Red-tailed Hawk. These beautiful native raptors can be viewed during ACES regular business hours. During the summer, ACES' Bird of Prey program runs Monday - Saturday at 4PM. Hallam Lake is a permitted raptor rehabilitation center. Our resident birds cannot fly or hunt, and are therefore unreleasable. 

Become a Junior Naturalist (currently unavailable)

Kids of all ages are invited to become official ACES Junior Naturalists by exploring the Hallam Lake nature preserve and recording their findings! Borrow an Adventure Backpack with all of the tools you need to complete the Junior Naturalist Activity Guide, featuring engaging, age-appropriate activities that exercise your skills as a scientist, observer, and explorer. Earn your ACES Junior Naturalist Badge by completing the required number of activities for your age group and taking the Naturalist oath.