nonprofit

Aspen Center for Environmental Studies (ACES)

Founded in 1968, ACES runs naturalist-led programming across three valley sites — Hallam Lake, Rock Bottom Ranch, and Catto Center at Toklat — including guided bird walks, free summer naturalist hikes, and winter snowshoe tours.

Birding✓ Verified 2026-06-26

Tuesday Birding at Hallam Lake

Aspen Center for Environmental Studies (ACES)

Select / bi-weekly Tuesday mornings, summer into early fall, alternating Hallam Lake and Rock Bottom Ranch

ACES Hallam Lake Nature Preserve, Aspen (some dates at Rock Bottom Ranch, Basalt)

Beginner-friendlyNo-dropPaidSummer

A roughly three-hour morning walk for birders of all levels, led by veteran naturalist Rebecca Weiss. Discounted for ACES members. Runs select Tuesdays — confirm the date and location before going.