Afternoon storm risk is the line that matters. Everything else is comfort. In summer, plan to be off the ridge before the build-up starts, not as it starts. Forecast for the summit point, adjusted for its elevation · data from Open-Meteo.
Alternate route · West Ridge from Guanella Pass
Overview
This route climbs Mount Blue Sky from Guanella Pass. It starts on the Mount Bierstadt trail, crosses the willows of Scott Gomer Creek, climbs a gully on the far side of the valley, and then follows Blue Sky's long west ridge to the top. It is a quieter alternative to the more common approaches.
The route is Class 2. The willows can be wet and the trail through them is faint. The last mile on the ridge is mostly boulder hopping with cairns and bits of trail. It suits hikers who are fine with some route-finding and rocky ground.
Plan on about 9.25 miles round trip with 3,100 feet of gain. Most people take 7 to 9 hours. Remember that you have to climb back up to the pass at the end of the day.
Plan of the day
Start by
By 5 a.m. You are above treeline the entire day.
Turnaround
If you are not at the start of the west ridge near 13,700 feet by 10 a.m., turn around. The ridge is still about a mile of slow boulder travel.
Crux
The mile of boulders along the west ridge. It is not hard, but it is slow and tiring.
Route-finding
Moderate. Finding the faint trail through the willows and the gully entrance takes care. Up high, other peaks are hard to pick out, so once the bump on the ridge's west end comes into view, head for it.
Water
Scott Gomer Creek near the start. None higher up. Carry 3 liters and filter anything from the creek.
Coming from the north, leave Interstate 70 at the Georgetown exit. Go through Georgetown, following the Guanella Pass Scenic Byway signs. The pass top, at about 11,700 feet, is roughly 12 miles on. There are two large paved lots; leave your car in either. The upper lot, on the west side, has restrooms.
From the south, take U.S. 285 to Grant, a town about 12 miles west of Bailey. Head north on the Guanella Pass Scenic Byway; the pass is about 13 miles up. The lots fill early on summer weekends.
Talus and screeScramblingTundraRidgeExposed to lightning
The line is elevation, the band underneath is the ground, and the numbered dots match the steps below. Mileage and elevations are approximate.
1
Guanella Pass trailhead 11,700' · 0 mi
Find the Mount Bierstadt trail near the east-side lot. Follow it downhill to the east toward Scott Gomer Creek.
2
Scott Gomer Creek 11,500' · 0.9 mi
For almost a mile the trail twists among willows before it reaches the creek. Cross it and pass a large boulder on your left.
Watch for: Fill water here.
3
Clearing past the creek 11,500' · 1 mi
In a small clearing, look for a faint trail that splits off from the Bierstadt trail. Follow it into the willows, heading east and then northeast along the creek.
Watch for: The ground here is often wet or flooded. The faint trail is easy to lose.
4
Creek near a boulder 11,600' · 1.6 mi
Near 11,600 feet the faint trail meets the creek again beside a boulder. Turn right and keep going through the willows. A gully appears to the east as you near the head of the creek.
5
Clearing below the gully 11,700' · 2.2 mi
After a large clearing, the trail climbs through ledges along the gully's right side; follow it.
6
Enter the gully 12,300' · 2.7 mi
Near 12,300 feet, move into the gully and climb its left side. For about 600 feet of climbing, keep to the left side or close to the middle.
Watch for: Loose rock in the gully. Watch for rocks knocked down by people above.
7
Top of the gully 13,100' · 3.3 mi
Above 13,100 feet the gully widens. The trail leaves on its left side and the slope eases. The view opens up.
8
Start of the west ridge 13,700' · 3.8 mi
Continue up until the bump on the ridge's west end is in sight, then walk over to it. Here, drop slightly right and follow cairns below the ridge crest.
Watch for: Other peaks nearby are hard to tell apart here. Take note of where you came up so you can find the gully on the way down.
9
Boulders below the crest 13,900' · 4.2 mi
Most of the last mile is boulders, with cairns and short trail sections. Take your time and use the cairns.
Watch for: Boulders can shift. Test them before you step.
10
Summit trail 14,200' · 4.55 mi
The ground gets easier near the top. Just below the summit you meet the tourist trail from the summit parking area.
11
Summit of Mount Blue Sky 14,268' · 4.6 mi
Walk up to the top.
Watch for: The summit area may be busy with people who drove up.
Getting down
Go back the same way. Follow the cairns along the ridge, then find the top of the gully and descend it. On the way out, stay on the side of the creek you used coming in. Save energy for the final climb of about 200 feet from the creek back up to the pass.
If things go wrong
The fastest way off is back down the gully to the creek valley. Do not try to drop off the ridge elsewhere; the terrain is unfamiliar and can be steep. In a storm, get off the ridge and down the gully as quickly as it is safe.
Other routes
Every way up Mount Blue Sky we list, with its class.
This describes the route in its usual season. Distances and elevations are close estimates for planning. Snow, ice, rockfall, a washed-out road or an afternoon storm can make it a very different climb. Check recent conditions the week you go and turn around when the day tells you to.
