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Four Pass Loop

 49 votes

27.1 Miles 43.6 Kilometers






7,734' 2,357 m


-7,735' -2,358 m


12,460' 3,798 m


9,567' 2,916 m



Avg Grade (6°)


Max Grade (29°)



An all-time journey over four 12,500' alpine passes, circumnavigating the Maroon Bells.

Jason Smith


If you're planning on doing this as an overnight, you must perform a self check-in and fill out an overnight permit. For more information on camping, download this PDF.
Up and over four incredible 12,000'+ mountain passes around the Maroon Bells Wilderness. People do this as a 4-day backpack... and it's a common 1-day run!
Features: Birding — Fall Colors — Lake — River/Creek — Views — Waterfall — Wildflowers — Wildlife
Dogs: Leashed

Need to Know

To access the trailhead at Maroon Lake, you must enter the Maroon Bells Scenic Area before 8am or after 5pm to access with a vehicle, which a $10 entrance fee is required. Otherwise, shuttle buses run for all visitors arriving between 8am-5pm. For more info click here.


Begin at the Maroon Snowmass Trailhead. This route is described counterclockwise, going Buckskin Pass, Trail Rider Pass, Frigid Air Pass, West Maroon Pass. Either way is great.

Proceed South on Maroon Snowmass Trail, climbing gradually over 1.5 miles. Make a right at a signed T-intersection headed for Buckskin Pass (Buckskin Pass Trail). Nowhere to go but up with spectacular views of N. Maroon (14,014') blowing up to your left as you crest treeline.

From the top turn around to savor the early morning sun on Pyramid Peak (14,018'), eye up the trail descending right and take it down toward the densely forested Snowmass Creek drainage. After about 3 miles from the top of Buckskin, take the first left onto Geneva Lake Trail at a t-intersection. In early August 2014, this critical juncture was not signed. Consult the Trail Run Project mobile app here to make sure you make the turn.

Let the pain begin as you ascend southwestward to Trail Rider Pass over the stunning Snowmass Lake and under the eastern flanks of the hulking Snowmass Mountain (14,092').

From Trail Rider summit (12,500'), enjoy sweeping views of the remote West Elks & brace your skeleton for the steepest, most jarring descent of the day.

Note: If you encounter dangerous weather, a possible bailout is to exit to the southwest at the Geneva Lake trailhead, where you can probably hitch a ride with a 4x4 on the Lead King Loop down to Marble to make a pickup call.

About two miles off the top of Trail Rider, keep a sharp eye out for your next critical left turn, onto the unsigned North Fork Cutoff Trail. For the next mile you'll traverse southeast on a steep hillside until merging with North Fork Crystal River. If you need a break, this is a good spot to fill up water and get off your feet. After another mile, look for a ridiculous waterfall & enter the pain cave once again as you switchback above the falls to enter the otherworldly Fravert Basin.

From here, it's 2.75 miles under Maroon Peak (14,156') through unreal alpine terrain to the top of Frigid Air Pass. Keep some gas in the tank to savor this section. From Frigid Air summit (12,500'), take heart because you have just two miles and much less vertical relief to Maroon Pass.

Halfway between the passes, go straight toward Maroon at a T, meeting West Maroon Trail. Punch it over your final 12,500' pass, and cruise the last seven miles down the West Maroon Creek drainage to your cooler.

Flora & Fauna

More wildflowers than you can count...


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5.0 from 49 votes

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Sep 22, 2017
Whitney Cook
Sep 1, 2017
Michael Reschly
Aug 26, 2017
Weilong You
28mi — 9h 54m
Aug 19, 2017
Amanda Stone
Aug 12, 2017
Anthony Carroll
Jul 22, 2017
Jerret Halter
Jul 6, 2017
Sankalp Shiva
Sep 26, 2016
Andrea Thorpe
on 9/25, a lot of snow and mud; slushy and icy in the afternoon.

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  5.0 from 49 votes


in Aspen


  5.0 from 49 votes
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Are there places to refil water bottles? Or do I need a filter? If so where are the stations? Aug 24, 2016
There's some serious warning about lighting risk after 11AM, any recommendations on how to cope with that? when would be a good start time? Aug 7, 2017
Great late-August run. Plenty of water, great weather. Truly world class! Sep 4, 2017

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