Overview
Pearl Mountain rises above Pearl Pass, the rough 4WD road between Ashcroft and Crested Butte. From the Castle Creek ford near Ashcroft, you walk the Pearl Pass Road past two backcountry ski huts, leave it at treeline, and climb a north ridge and gully to the northwest ridge and the summit.
It is Class 2, mostly tundra and fairly stable talus, with lots of wildflowers and big views of Castle Peak.
From the ford it is about 8.8 miles round trip with about 3,180 feet of gain. Mileage and gain are our estimates. A good short-wheelbase 4WD can drive much closer and cut it to a short half day. Oyster Peak is an easy add-on.
Plan of the day
By 7 a.m. from the ford.
Be on the northwest ridge by 11 a.m.
Nothing hard. Rubble on the upper ridge.
Easy. Leave the Pearl Pass road at treeline and head for the western of Pearl's two north ridges.
Castle Creek and streams in the bowl. Filter it.
Getting to the trailhead
Castle Creek
From the roundabout on Highway 82 just west of Aspen, take Castle Creek Road (County Road 15) about 11 miles to the old Ashcroft townsite. Continue 2 miles past the Toklat Lodge to a junction with a kiosk and room for several cars on the west side of the road. Low-clearance cars should park here.
Turn right onto the Pearl Pass Road (FR 102). It gets much rougher after about half a mile. After about 1.4 miles it fords Castle Creek, and there is a footbridge for hikers. We start the route at this ford. The ford can be deep during spring runoff.
Past the ford, a high-clearance 4WD can keep going, slowly, over very rocky road to the Pearl Pass junction and to the end of the road, in the high basin below Castle Peak's north side (about 12,775 feet). Fallen trees can block the way. There are no Forest Service campgrounds along the road, but there are a few primitive sites on FR 102 on both sides of the creek. Much of the land along Castle Creek Road is private.
Base towns and camping for this climb
Coming from out of state? See Lodging & Camping for how free camping works, what is closed this year and where to stay.
Before you go
Check these the week of your climb.
Official forecast
The National Weather Service forecast for the summit area, hour by hour. Look for thunderstorm chances and wind above treeline.
NWS point forecast →Directions to the trailhead
Castle Creek. Road conditions near the trailhead change after storms. Check your clearance and have a backup plan for a lower lot.
Get directions →Roads and highways
Closures, construction and winter conditions on the highways that get you there.
COtrip road conditions →Closures and fire rules
Trail closures, fire bans and other alerts from the Forest Service in Colorado. For the latest on your trailhead, call the local ranger district.
Forest Service alerts →Snow on the route?
From fall through early summer, any snow slope can slide. Check the avalanche forecast before you go.
Avalanche forecast →Cell signal
Most trailheads and many summits have little or no signal. Check coverage near the trailhead and carry a satellite messenger or beacon if you can.
FCC coverage map →