Chicago Basin
~3 days · 12.7 mi · easy · Point-to-point
Quick facts
What the Chicago Basin is known for
Chicago Basin is a classic backcountry destination deep in Colorado's Weminuche Wilderness, set in a high cirque ringed by fourteeners in the San Juan Mountains. The trip is typically an out-and-back that follows Needle Creek up from the Animas River, and it is famous for being reached by riding the Durango & Silverton narrow-gauge railroad to the Needleton stop rather than by road. From a basecamp in the basin, climbers access the Chicago Basin fourteeners, including Mount Eolus, Sunlight Peak, and Windom Peak. It is known as one of the most remote fourteener approaches in the state.
Elevation profile
Elevation ranges from 8,235 ft to 13,028 ft over 12.7 mi. Measured from OSM geometry (approximate).
- Uphill 2.0 mi · 16%
- Downhill 10.1 mi · 82%
- Flat 0.2 mi · 1%
Ridgefold breaks every route into uphill, downhill, and flat — see the full per-day breakdown in the app.
How hard is the Chicago Basin?
On the Ridgefold Difficulty Index, the Chicago Basin scores 14/100, a relative rating across the 569 trails we've mapped, blending distance, elevation gain, and steepness. It is a comparison within our set, not an official rating.
Best season & permits
Season: Summer into early fall (roughly July through September) is the standard season, once high-country snow has melted; afternoon thunderstorms are a daily hazard above treeline.
Permits: No permit is currently required to backpack in the Weminuche Wilderness, though standard wilderness regulations and bear-canister/food-storage rules apply, and the train access requires a ticket reservation.
Official trail & permit info
Always confirm current conditions, closures, and permit rules with the managing authority before your trip.
Frequently asked questions
How many days does the Chicago Basin take?
Most backpackers hike the Chicago Basin in about 3 days (2 nights out) over its 12.7 miles, though pace varies with fitness and conditions.
How much elevation gain is on the Chicago Basin?
The Chicago Basin climbs roughly 1,696 ft total — about 134 ft per mile, topping out near 13,028 ft.
When is the best time to hike the Chicago Basin?
Summer into early fall (roughly July through September) is the standard season, once high-country snow has melted; afternoon thunderstorms are a daily hazard above treeline.
Do you need a permit for the Chicago Basin?
No permit is currently required to backpack in the Weminuche Wilderness, though standard wilderness regulations and bear-canister/food-storage rules apply, and the train access requires a ticket reservation.
Related trails
Sources & attribution
Route geometry and stats derived from OpenStreetMap (© OpenStreetMap contributors, ODbL) — source relation. Stats are approximate and may differ from official surveys; permit rules and conditions change — verify with the managing authority before your trip. Last reviewed July 2026.