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.
Centennial 13er · South Ridge and Couloir
Overview
Cathedral Peak is a jagged Elk Range summit that towers over Cathedral Lake near Ashcroft, south of Aspen. The day starts on a good trail to the lake. From there you leave the trail, cross a rubble-filled basin, climb a steep gully to a notch on the south ridge, and pick your way north along a broken ridge to the top.
This is a Class 3 route on rotten Elk Range rock. The gully is steep and loose. Early in the summer it holds hard snow, and you need an ice axe and crampons and the skill to use them. Later it melts out to a slope of sand, gravel and loose stones where every step slides back. Rockfall from people above is a real danger. The upper ridge has cliff bands, a notch and serious drop-offs. This is not a peak for beginners.
The round trip is 8.6 miles with about 4,025 feet of gain. Most parties need 8 to 10 hours. Many people camp near the lake and climb from there, which shortens the summit day to about 3 miles round trip.
Plan of the day
Start by
By 5 a.m. from the trailhead, or by 6 a.m. if camped at the lake. You want to be down out of the gully before afternoon storms, and early starts also mean firmer snow.
Turnaround
If you are not at the top of the gully by 10:30 a.m., or storms are building over the Elks, turn around. Do not start up the gully late in the day.
Crux
The steep gully from the basin to the south ridge. On snow it needs axe and crampons; dry, it is a loose, sliding slope with rockfall. The cliff band and notch just below the summit are the second hard spot.
Route-finding
The trail to the lake is clear. Above the lake there is no trail you can count on. The key is picking the right gully: of the three that rise from the basin, you want the one farthest north (right, as you face the peak).
Water
Pine Creek and Cathedral Lake have plenty of water. The upper basin has snowmelt early in the season but often none later. Filter everything.
From the roundabout on Highway 82 at the west edge of Aspen, take Castle Creek Road south. Drive about 11 miles to the old town site of Ashcroft. Just under a mile past Ashcroft, turn right (west) onto a gravel road and follow it half a mile to the trailhead. If you reach the Ashcroft Ski Touring Center and Pine Creek Cookhouse, you just passed the turn.
The trailhead road is graded gravel with some potholes and is fine for passenger cars. The lot is small and fills early on summer weekends, when cars line the road below it. Arrive early. If you plan to camp at the lake, follow current forest service rules for overnight stays; bear-proof food storage is required there.
Trail in the treesTalus and screeTundraRidgeScramblingExposed 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
Cathedral Lake trailhead 9,910' · 0 mi
The trail leaves the lot and climbs into aspen forest. It is steep from the start, so pace yourself; the climb to the lake is nearly 2,000 feet.
2
Aspen slopes 10,200' · 0.5 mi
The trail heads southwest across the hillside above the Ashcroft area. Aspen give way to mixed forest. Below you is the Castle Creek valley.
3
Pine Creek canyon 10,600' · 1.2 mi
The trail swings into the Pine Creek drainage and stays on the north side of the creek. You enter the Maroon Bells-Snowmass Wilderness here. The grade gets steeper.
4
Willow meadows 11,000' · 1.8 mi
The valley opens up. The trail climbs through a few sets of switchbacks and into an area with more willows than trees. The jagged skyline of the Cathedral massif comes into view ahead.
5
Talus crossing 11,300' · 2.2 mi
The trail crosses a broad talus field on a built path. Right after it, a long series of tight, steep switchbacks climbs the headwall.
Watch for: Rocks on the switchbacks can be knocked down by hikers above. Keep an eye up.
6
Top of switchbacks 11,800' · 2.6 mi
The trail tops out and flattens. A trail going right leads toward Electric Pass. Stay left for the lake, which is about 15 more minutes.
Watch for: Do not take the right fork unless you mean to go to Electric Pass.
7
Cathedral Lake 11,866' · 2.9 mi
The lake sits in a deep bowl under the peak's east face. Walk to the lake's north end and cross its outlet stream. Look across to the northwest shore for a big green patch of willow and tundra, with fainter green patches above it.
Watch for: No camping right on the lake shore.
8
Green tundra patches 12,050' · 3.1 mi
Cross the outlet and head west to the green patch. Climb along its east edge to stay out of the willows. Link the grassy patches above to avoid as much loose rock as you can.
9
Southeast basin 12,400' · 3.4 mi
Enter the rubble-filled basin southeast of the summit. Much of it is a rock glacier. Look up at the ridge south of the summit and find three gullies. You want the one on the far right, which drops from the first big saddle south of the top.
Watch for: Picking the wrong gully leads into worse rock. Confirm it before you commit.
10
Base of the gully 12,800' · 3.7 mi
Walk over rubble, or snow early in the season, to the foot of the gully. This is the place to put on your helmet and, if there is snow, crampons, and to get your ice axe in hand.
Watch for: Rockfall. Space out your group or climb close together so falling rocks cannot build speed.
11
Top of the gully 13,500' · 4 mi
Climb the steep gully to the saddle on the south ridge. On snow, kick steps and move slowly. When dry, stay near the edges where firmer rock gives better footing. Early in the season a cornice may hang over the top; the left side often melts out first.
Watch for: Do not climb under a cornice. Do not stand directly below other climbers.
12
South ridge cliff bands 13,750' · 4.15 mi
Turn north and follow the ridge toward the summit. Several small cliff bands cross the ridge. Weave through and around them on ledges and loose broken rock. It is slow going.
Watch for: Test every hold. Much of the rock is loose.
13
Notch below the summit 13,850' · 4.25 mi
Just before the top flattens out, a larger cliff band and a small notch block the crest. Drop a little to the west side to get around it, then climb back to the ridge.
Watch for: Real exposure here. Take your time and keep three points of contact on the rock.
14
Summit 13,952' · 4.3 mi
The summit is a fairly flat, rocky top. Much of the Elk Range is in view, with Cathedral Lake far below. Before you leave, look south and pick out the notch at the top of your gully.
Watch for: Start down early. The descent of the gully is slower than the climb.
Landmarks to know
Aspen forest and the Pine Creek canyon on the lower trail
A large talus field, then steep switchbacks up a headwall
Trail fork at the top of the switchbacks: right to Electric Pass, left to the lake
Cathedral Lake under the peak's east face
Big green willow and tundra patch above the northwest shore
Three gullies above the rock glacier; take the far right one
Saddle on the south ridge at the top of the gully
Cliff bands and a small notch just below the flat summit
Getting down
Go back the way you came. The most common mistake is missing the top of the correct gully on the way back along the ridge. Watch for the saddle you came up and do not drop into a gully you did not climb. The notch below the summit is again passed on the west side.
The gully is harder going down. On snow, face in and down-climb with your axe unless you are sure you can self-arrest; do not glissade a slope this steep with rocks at the bottom. When dry, move one at a time or stay close together, and shout if you knock anything loose. Once back at the lake, the trail is easy, but the steep switchbacks are hard on tired knees.
If things go wrong
Below the gully, the basin and the lake are safe ground and you can simply walk out. Once you are in the gully or on the ridge, the safest way down is still the gully you climbed; do not try to shortcut down the southeast face gullies, which are loose and cliffy. If a storm hits while you are on the ridge, get down into the gully and below the rock as fast as is safe. If someone is injured, stabilize them, keep them warm, and call 911. The Pine Creek trail is well traveled, so other hikers may be able to help carry word out.
3D flyover
Press play to fly the South Ridge and Couloir. The graph shows elevation along the way and how much you gain each mile. Open full screen.
For planning only. The line is traced from open map data, not walked in the field, and off-trail parts are drawn straight. Load it in your GPS app to see the route, but navigate with your eyes, a map and the route description.
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.
Other routes
Every way up Cathedral Peak we list, with its class.
This describes the route on a dry summer day. Snow, ice, 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.