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.
Colorado 13er · East Ridge from UN 13,559
Overview
UN 13,173 sits just west of UN 13,559 above Twin Lakes, north of Crested Butte. The usual way is to climb UN 13,559 first from Twin Lakes, then follow the connecting ridge west. Part of that ridge drops off in a steep, broken mess of rock that has to be downclimbed carefully.
The ridge is Class 3, steep, exposed and loose, and took one strong party almost two hours. It may be the hardest traverse in this area. To skip it, climb the rock glacier northwest of Twin Lakes to the saddle just east of the summit, which keeps it at Class 2+.
The round trip with UN 13,559 is about 9.35 miles with 3,700 feet of gain. The trailhead needs a high-clearance vehicle.
Plan of the day
Start by
By 6 a.m. from the trailhead.
Turnaround
Be on UN 13,559 by 10:30 a.m. The ridge takes a couple of hours.
Crux
Downclimbing the broken section of ridge west of the unnamed middle point.
Route-finding
Difficult on the ridge. Stay on the crest; there is no easy way around the broken section. Near the summit, look for a break in the last rock band.
Water
Middle Brush Creek, Twin Lakes and small ponds above them. Filter it.
From Gunnison, take Highway 135 north through Almont toward Crested Butte. About 2 miles before Crested Butte, turn right onto County Road 738, the Pearl Pass Road. It starts paved through a subdivision, then turns to gravel.
Passenger cars can go 4 to 5 miles, to just past where the East River comes in. Park at a primitive camping area on the right, just as the road starts to climb. With high clearance, keep going: stay right at a junction about a mile later, ford West Brush Creek, and drive about 4.5 more miles to the Twin Lakes parking, which turns off the road to the left.
There are good primitive campsites with some trees at the trailhead, often busy on weekends.
Trail in the treesTundraTalus and screeRidgeExposed 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
Twin Lakes trailhead 10,425' · 0 mi
Cross Middle Brush Creek (wade it or find a way across), climb north a little, then turn northwest on Trail 402 toward Twin Lakes.
Watch for: The crossing can be high in early summer.
2
Into the wilderness 10,900' · 1.5 mi
The trail crosses open ground and patches of high forest on the east side of the creek, then enters the Maroon-Snowmass Wilderness. Overnight visitors must fill out a permit at the boundary.
3
Willows 11,300' · 2.7 mi
About half a mile below the lakes the trail crosses to the west side of the creek and pushes through thick, wet willows. It can be hard to follow here.
4
Twin Lakes 11,580' · 3.2 mi
Reach the north end of the upper lake. There are a few campsites near the lower lake, and more on tundra benches above.
5
Upper basin 12,350' · 3.5 mi
From the north end of the lake, head north, climbing roughly 800 feet, to a higher basin right below the south face.
6
Rock bands 12,900' · 3.75 mi
Climb a talus slope covered in grass through several cliff bands, zigzagging and trending toward the west ridge. You can also go all the way to the west ridge and follow it east to the top.
7
Dark gully and ramp 13,250' · 3.85 mi
About 300 feet below the summit, scramble a narrow gully of darker rock, then follow a ramp that slopes up to the east.
Watch for: Class 3. Loose rock.
8
Southeast ridge 13,350' · 3.9 mi
The ramp comes out at a small saddle on the southeast ridge about 200 feet below the top, with a great view of Castle Peak's jagged ridge.
9
Summit 13,559' · 3.95 mi
Walk and scramble up easier red rock to the summit.
10
Middle point 13,300' · 4.3 mi
Drop easily to the first saddle west of UN 13,559 and walk up the ridge to an unnamed high point.
11
Broken section 13,100' · 4.6 mi
About 100 yards past the point, the ridge falls away into a steep, broken jumble. Downclimb it carefully along the crest.
Watch for: Class 3, exposed and very loose. Go one at a time.
12
Saddle 12,950' · 4.8 mi
Traverse more easily to the next saddle.
13
Summit 13,173' · 5.05 mi
A rock band below the summit has an easy break. Walk through it to the top. Below to the south is the basin west of Twin Lakes, a nice spot for a first-night camp.
Getting down
Go back to the saddle just east of the summit and descend southeast through broken rock and a rock glacier into the basin northwest of the lakes. Then walk down flowery grass back to Twin Lakes. This is also the easier way up if you want UN 13,173 alone.
If things go wrong
Before the broken section, go back to UN 13,559 and down its south face route.
3D flyover
No 3D flyover for this peak
Past Twin Lakes the route climbs trailless slopes and a rough ridge. A flyover only works when there is a set trail to trace. Without one, the line would be a guess, and a guess could send you the wrong way on the mountain. Use the step-by-step route with a good map and GPS track instead.
See the trail on video
No video yet
We haven’t found a good video of this route that matches the way we describe it. The route strip, junctions and 3D flyover show the way in the meantime.
This describes the route on a dry summer day. Most 13ers see few people, so there may be no one along behind you. Check recent conditions the week you go, carry a map, tell someone your plan, and turn around when the day tells you to.