Bucket List · Bucket list route
Four Pass Loop
Twenty-six miles around the Maroon Bells, over West Maroon, Frigid Air, Trail Rider, and Buckskin Passes, all above 12,400 feet. It is the most beautiful day of running available in Colorado and it is only twenty-six miles, which is a trap.
- Distance
- ~26 mi
- Climbing
- ~7,800 ft
- Passes
- 4All above 12,400 ft
- Typical time
- 7 to 12 hours
- Access
- Maroon Lake reservation
- Season
- Mid-July to Sept
The loop leaves Maroon Lake outside Aspen and circles the Maroon Bells through wildflower basins, over four alpine passes, past Snowmass Lake, and back. The scenery is absurd throughout: the Bells themselves, Geneva Lake, the wildflower meadows below Frigid Air in late July.
The number that catches people out is altitude, not distance. You never drop below about 9,600 feet, you cross four passes over 12,400, and afternoon thunderstorms in the Colorado high country are a genuine lightning risk on exposed passes. Twenty-six miles at that elevation with 7,800 feet of climbing is a full day.
How to get in
- PermitMaroon Lake access reservation
Vehicle and shuttle access to the Maroon Lake trailhead is reservation-controlled during the season through the Aspen Chamber system, and it books out. This is the actual gate on the Four Pass Loop, and people miss it because they're looking for a wilderness permit that doesn't exist for day use.
- Self-supportedDay travel
Running the loop in a day requires no wilderness permit. Overnight camping in the Maroon Bells-Snowmass Wilderness does require a permit, allocated through recreation.gov, and the popular sites go quickly.
Running it well
- Start at first light. Colorado afternoon thunderstorms build from about 1 p.m. and you do not want to be on Trail Rider or Buckskin when they do.
- Direction is a real choice. Clockwise gets West Maroon first and the long Snowmass section later. Counterclockwise front-loads Buckskin. Both work.
- Acclimate. If you're coming from sea level, give yourself a couple of days in Aspen or accept that you'll walk more of the passes.
- Creek crossings can be significant in early season snowmelt.
- Late July is peak wildflower. Early September is peak aspen. Both are worth timing for.
Questions runners actually ask
Do I need a permit for the Four Pass Loop?
Not for day travel in the wilderness, but access to the Maroon Lake trailhead is reservation-controlled during the season and books out. Overnight camping requires a permit through recreation.gov.
How hard is it?
Twenty-six miles with 7,800 feet of climbing and four passes above 12,400 feet. The altitude makes it considerably harder than the distance suggests, especially for visitors.
Go to the source
Entry rules, dates, standards, fees, and odds change every single year, and the interesting races change them the most. Use this guide to build the plan; use the official site to confirm the details before you book anything.
If this is your kind of thing
Need the races in between? The hard part of a bucket list year is everything else on the calendar: the qualifier, the tune-up, the long run with a bib on.