Grand Couloir Mt Aetna Guide

May 3, 2023 The Virtual Sherpa Comments 0 Comment

The Grand Couloir on Mt Aetna is a 2,900ft long moderate backcountry ski run located near Monarch Pass in Central Colorado. This south / southwest facing couloir has a sustained grade of about 35 degrees with the steepest parts right around 40°. The Grand Couloir is a great introduction to snow climbing and backcountry skiing as it is very accessible and while avalanche prone, fairly easy to manage risks. This line is typically “in” from later December through early May.

Grand Couloir Quick Facts

Virtual Trail Guide: Grand Couloir Mt Aetna

Grand Couloir Mt Aetna Rating: ★★★★★ (5/5 Stars)

Distance: 7 Miles RT (From Monarch Pass)

Elevation Start: 9,679ft

High Point: 13,745ft

Total Elevation Gain: 4,150ft

Estimated Time to Complete: 5-6 Hours RT

Difficulty: Moderate What does this mean?

Class: Class 2 – What does this mean?

Season: December – May

Snow Climb Grade: Easy: 35-40 Degrees at its steepest grade

Check the Weather Forecast

Avalanche Risk: The Grand Couloir in the Winter and Spring does present avalanche risk, so please understand the conditions and risks before heading out. Watch this video for basic avalanche information.

Directions to Grand Couloir

Trailhead: Lower Boss Lake TH

Getting Here: From Poncha Springs/ Points East: At the intersection of 285 and 50, continue west on US50 for 12.2 miles to reach the start of the trailhead just past Monarch Snowmobile Tours & Rentals on your right. If you have driven past the Monarch Mountain Lodge, you have gone too far.

From Monarch Pass/Points West: Navigate to the top of Monarch Pass and continue down the east side until you reach Monarch Snowmobile Tours & Rentals on your left. If you have driven past the Monarch Mountain Lodge you have gone too far.

From either direction, once you have found the lower trailhead, you will typically want to park here. Although driving up further may be enticing, there is almost no chance the line will still be in if you are able to drive all the way to Boss Lake TH (the next logical spot to park).

Parking: The lower Boss Lake/Mt Aetna TH can fit about 10 cars if people park with common sense. Note that parking past signed areas may result in a ticket or tow. There are no restrooms at this trailhead and parking will likely fill up by 8AM on most Spring and later Winter weekends as this is a popular line.

Fee: No fee is required

Summary

Dogs: I would not recommend bringing a dog up any couloir.

Camping: Camping in this area is extremely tricky, especially during winter or spring months. There is no camping at the TH or in the immediate area surrounding Mt Aetna due to plots of private land that surround the TH. If the snow has melted out a bit, you are able to camp in a few spots higher up on Forest Road 230, but this is not a sure bet and likely will not be available while the line is still in.

Make it a Loop: For ambitious skiers, you could skin/boot up neighboring Taylor Mountain and then take the ridge over to Mt Aetna for a descent down the Grand Couloir. However, this guide will not cover any aspects of that hike. There are also a number of other ski lines in the basin to the West of Mt Aetna.

Trail X Factors: Parking & West Facing Couloir Conditions

I discovered the hard way that this parking lot and line in general, is very popular. If you plan on tackling this line during the winter or spring, I would highly recommend an early arrival so that you can snag a spot. Otherwise, your options are very crappy and limited to parking elsewhere. Although you could park in the neighboring Snowmobile tour lot or hotel, I would not encourage it.

As many of you may know, west facing slopes in the Colorado mountains tend to melt out first and hold significantly less snow than some of the other aspects. Since the Grand Couloir faces South/Southwest, depending on the year, the couloir itself could get pretty sharky on the left side when climbing or descending. Be sure to check snow depth before giving yourself a core shot.

Hike Tip: Before heading out to attempt ANY winter hike or couloir be sure to understand avalanche conditions. Grand Couloir faces South/Southwest so be sure to check for overnight temps for a solid freeze and plan to start and end early to avoid any wet slides.

Best Views: Until you break the treeline, there are no views. However, once above, the views of the surrounding mountains and basin are beautiful. As you climb higher in the couloir, the views to your West and South get better with each kickstep into the snow. From the summit of Mt Aetna, views are absolutely stunning in all directions.