Four Pass Loop
Elk Mountains, CO
Elevation Profile
Current Conditions
Bottom Line
Four Pass Loop in mid-November is a serious undertaking — four passes above 12,000 ft with under 10.5 hours of daylight and overnight lows in the teens. The avalanche danger is Low and weather window is clean, but daylight is your binding constraint. Plan each day's pass crossings to finish before 4 PM.
39°/18°F · Partly Sunny
Low (1/5)
0" depth
Elevated flows · 5 gauges
No active fires within 50 miles
10h 13m daylight · Sunrise 6:46 AM · Sunset 4:59 PM
Full Briefing
The weather window for November 10–13 is about as good as late-season gets in the Elk Range. Highs in the upper 30s to low 40s, lows in the teens, light winds 5–10 mph WNW, and mostly clear skies throughout. No precipitation in the forecast, which means stable trail conditions and no new snow loading on the passes. The avalanche bulletin is clean — Low danger at all elevations with no identified problems. That's not a caveat, that's genuinely good news for high-alpine travel in November.
The SNOTEL data shows near-zero snowpack at the reporting stations, which are at much lower elevations than the Four Pass Loop's high points (Frigid Air Pass at 12,415 ft, West Maroon at 12,500 ft, Trail Rider at 12,420 ft, Buckskin at 12,462 ft). Expect patchy snow and potential ice on north-facing slopes approaching and descending each pass, especially in shaded couloirs. With overnight temps dropping to 18–23°F, any wet or packed snow from afternoon sun will refreeze hard by morning. Microspikes or traction devices are worth having accessible for the early-morning pass crossings.
The stream flow data in the raw feed references California gauges, which are not applicable to this route — disregard those numbers. Maroon Creek and the drainages on the Four Pass Loop in early November are typically low and easy to cross; cold temperatures suppress snowmelt and there's no precipitation driving flows. Water availability along the route will be limited by freezing — plan to melt snow at camp if water sources are iced over, particularly on the North Fork Crested Butte side.
Daylight is the real logistics problem here. You have 10 hours 13 minutes of usable light, with sunset at 4:59 PM. The Four Pass Loop is roughly 26 miles with 7,500 ft of gain. Doing it in three days means averaging nearly 9 miles and two passes per day on days one and two. Start moving by 7 AM each day. Prioritize getting over the high passes before 2 PM — not because of avalanche or weather risk, but because the low November sun drops fast and descending icy north-facing slopes in fading light is where this trip gets dangerous. Camp selection matters: get to your planned site early enough to have an hour of light for setup.
Waypoints
Maroon Lake
Start at Maroon Lake with views of the Maroon Bells. Take the bus from Aspen.
9,600 ft
West Maroon Pass
First pass at 12,500 ft. Views of Maroon Peak and Pyramid Peak.
12,300 ft
Frigid Air Pass
Second and highest pass. Steep approach from the Fravert Basin side.
12,500 ft
Trail Rider Pass
Third pass. Snowmass Lake visible from the descent.
12,201 ft
Buckskin Pass
Final pass with sweeping views back to the Maroon Bells.
12,300 ft
Return to Maroon Lake
Complete the loop back at Maroon Lake.
9,600 ft
Route Details
Distance
27.0 mi
Elevation Gain
10,000 ft
Elevation Loss
10,000 ft
Max Elevation
12,500 ft
Estimated Days
3
Trailhead
Maroon Lake Trailhead
Best Season
July through September. Snow on passes possible into July.
About This Route
The Four Pass Loop near Aspen, Colorado is one of the most popular backpacking routes in the state, circumnavigating the Maroon Bells-Snowmass Wilderness over four passes above 12,000 feet. The 27-mile loop can be completed in 2-4 days and offers non-stop alpine scenery. The route crosses West Maroon Pass, Frigid Air Pass, Trail Rider Pass, and Buckskin Pass, with each pass delivering panoramic views of the Elk Mountains. Between passes, the trail descends into wildflower-filled valleys with reliable water from snowmelt streams. The Maroon Bells themselves—perhaps Colorado's most iconic peaks—are visible from multiple points. The loop is best done counterclockwise, starting from Maroon Lake. Camping is available at designated sites in some valleys. The area sees heavy use in July and August. Bear canisters are required. Afternoon thunderstorms are almost guaranteed, so plan to be below treeline by noon.
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