Cathedral Peak lives up to its name when it first appears above Cathedral Lake: a jagged wall of spires and crumbling towers standing over one of the prettiest basins in the Elk Mountains. It rises in the Maroon Bells-Snowmass Wilderness above Castle Creek, north of Castle Peak, and ranks among Colorado's highest hundred summits. There is no trail to the top, and trip reports are the best read on current conditions.
The usual line is the south ridge and couloir route. It starts at the Cathedral Lake Trailhead, reachable by passenger car, and follows the Cathedral Lake Trail through aspen groves and a steep final set of switchbacks to the deep blue-green lake near 11,900 feet. From there hikers work through willows and tundra into the basin southeast of the summit, climb the northernmost of three couloirs to the ridge, skirt any cornice, and scramble the south ridge through small cliff bands to the summit. Expect about 8.6 miles and 4,025 feet of gain round trip, Class 3 moves with serious exposure, and loose, broken rock the whole way. The couloir often holds snow, so bring an ice axe and crampons.
Plenty of parties split it into an overnight at the campsites below the lake, which require a free overnight permit you self-register for at the trailhead. Fall turns the aspens on the approach gold, and the summit looks south toward Castle across some of the wildest ridgelines in the range.
