Four Pass Loop

Overview

Colorado's premier backpacking route crosses four mountain passes above 12,000 feet through the Maroon Bells-Snowmass Wilderness. A 3-4 day trek with stunning wildflower meadows, alpine lakes, and panoramic views of the Elk Mountains. The full route covers 28.1 miles as a loop with about 8,500 feet of climbing, and most hikers finish it in around 18 hours. It sits in the White River National Forest, near Aspen in Pitkin County, topping out at 12,500 feet.

Trail Highlights

How Hard Is It?

This is rated expert. The big 28.1-mile distance paired with serious 8,500 feet of gain is what sets the effort level. It runs as a loop, so you get new scenery the whole way and finish back at the trailhead. The high point is above 11,500 feet, where the thin air makes the climb feel harder than the numbers suggest. If you hike regularly, plan for roughly 18 hours of moving time; add a buffer for photos, snack stops, and the slower pace at altitude.

Best Time to Hike

The best seasons here are summer. Summer is the reliable window once the snow clears, though that also means the busiest trailheads and the daily afternoon thunderstorm risk. In Colorado the weather turns fast in the high country, so start early, aim to be heading down by early afternoon, and watch the sky. Lightning, not distance, is what turns most summer hikes around.

Getting to the Trailhead

The trailhead is in the White River National Forest, closest to Aspen (Pitkin County). A wilderness permit is required. Reserve it ahead of time, since quotas sell out for the popular dates. The parking coordinates are 39.0989, -106.9428; plug those into your map app rather than the trail name, since several Colorado trailheads share names. Mountain weather and road closures can change access, so confirm the access road is open before a long drive.

Dogs & Kids

Dogs are not allowed on this trail, which is common inside national parks and sensitive alpine areas. It is a tough one for young kids given the 28.1 miles and 8,500 feet of gain. Save it for older, trail-tested kids or go without them.

What to Pack

Pack the Colorado basics: more water than you expect, layers for a 30-degree temperature swing, sun protection for the high-altitude UV, and rain protection for the afternoon. For a big, serious hike like this one, the gear that earns its weight most is sturdy footwear and poles. Here is what we actually recommend for trails like this:

• ›hiking boots with real traction
• ›a packable rain shell
• ›trekking poles for the climb and descent
• ›a water filter for the longer day
• ›microspikes for snow and ice
• ›an insulating layer for the summit

Frequently Asked Questions