Formerly UN 13312 B
UN13,312 ("Oyster Peak" aka: West Pearl Mtn.) is an easy Class 2 summit located off Pearl Pass which connects Ashcroft with Crested Butte. In our route description, we have sequenced Oyster with Pearl Mtn. With a stock 4WD, you can make these two summits in a relatively short half day hike on largely tundra and fairly stable talus. Without 4WD, add at least four more miles of walking round-trip. This peak along with Pearl, can be accessed from either the Aspen/Ashcroft side or the Crested Butte side via the Pearl Pass road. Both summits are located just a short distance from that road. The road itself is quite rocky & rugged and is best driven by shorter bed 4WD with excellent ground clearance. Oyster Peak is actually connected to the 14er Castle peak by a stunningly rugged ridge often seen in photos of Castle. Lidar measurements increased elevation by 4 feet.
UN13,312 (Oyster Peak) SE Ridge Route
From the busy traffic circle on the west side of Aspen on SH82 and just east of the airport business center, take the exit for the Castle Creek Road (CR15) and drive a long 11 miles to the townsite of Ashcroft. Measure from the Toklat Lodge and drive another 2.0 miles south to an intersection at these coordinates: N 39° 01' 45.17" W 106° 48' 28.26". (Or from the Pine Creek Cookhouse and the Ashcroft Ski Touring Center located on the west side of the highway it's another .6 mile). There is a kiosk sign here and parking for a number of vehicles on the west side of the road. If in a passenger vehicle with lower clearance, you may want to park here, but some crossover types may still proceed to make a right turn and head SW on FR 102, aka: the Pearl Pass Road. (ON GE this is labelled CR 15D). At the aforementioned intersection, there is a paved road that continues due south and goes all the way to a mine/quarry on the northern flank of Star Peak. That road does not show on the unrevised USGS quad and other maps as well like FSTopo 2016. You do not want that road anyhow for the Castle Creek TH.
Once you've turned onto FR 102, drive SW for about 1.4 mile to a low water crossing of Castle Creek. In early runoff season, fording here could be problematic. Roach points out that about a half mile in on this road, it steepens and becomes "dramatically rougher." His more recent report validates what we also found in 1993. There is also a footbridge for hikers. It's been there at least since 1980. There are some at-large campsites along the way. If you have a higher clearance vehicle and don't mind the rougher road, continue to the stream crossing. This is what we are identifying as the trailhead. See coordinates above. On the other side of the creek and a little farther along are more campsites. Beyond this point, we recommend 4WD with good clearance if you want to drive farther. With an adequate 4WD, the road may be driven all the way up into the basin north of Castle Peak at 12,775 ft. In prior years, we have made it up here in both a Jeep Cherokee and a Toyota T-100. It is rough and slow going and downed trees that have not been cleared off may stymie progress. If you make it as far as the Pearl Pass junction, the road to Pearl Pass takes off to the left and begins a steep climb through the trees. The road is very rocky and is a challenge to drive. (See photo). Stream runoff on the road has washed away most dirt leaving only rocks to drive on. Once out of the trees, the difficulty moderates some for a while. There is room at the intersection for Pearl Pass and the Castle/Conundrum Basin for about two or three vehicles to park.
If continuing to drive north into the basin north of Castle, the last time we were on this road (2003), the roughest section came shortly after the Pearl Pass turnoff. It was not too difficult, but the remaining drive will be slow because the road remains rocky and rough. We were in a Toyota T-100 at the time.
There are no National Forest campgrounds along the road to Ashcroft. As mentioned before, there are a few at-large primitive sites along FR102 both before & after crossing Castle Creek. There may also be usable sites back near Ashcroft and around the turnoff for the Taylor Pass road. Also, on the road up to the Cathdral Lake TH, there are a couple of primitive sites. There is a lot of private property all along CR15. Be careful where you try to camp. As with most areas in the summer, weekend use is heavy and unoccupied camp spots difficult to locate.
From Pearl Mountain
Click thumbnail to view full-size photo + caption
Open This Route in a New Window
From the trailhead where FR 102 crosses Castle Creek, walk WSW up the road for 1.8 miles to the road a road junction. Turn left up the road marked for Pearl Pass (FR129) hike a short distance passing two switchbacks to the two back country ski huts of Tagert and Wilson-Green and these coordinates: N 39° 00' 11.16" W 106° 50' 20.74". These rental huts are frequently used for summer mountain bike trips and winter back country ski trips. They are not open for non-paying, general public use. As soon as you turn onto the Pearl Pass Road, conditions become quite a bit rougher. Shorter bed, 4WD vehicles will do best here. The road remains quite rocky until it climbs out of the forest and into the alpine zone. The streams of water that have flowed down the road have washed away almost all the dirt leaving behind only rubble to drive on. You may marvel at the thought of someone trying to bike this stretch. Also, before reaching the huts, there is one stream crossing over the south fork of Castle Creek.
Continue walking up the road generally south. Soon, it breaks out of the forest and then begins a series of switchbacks to gain altitude with more open groups of conifers close by. At some point, you may want to abandon the road and head off in the tundra, but it is possible to follow the road all the way to Pearl Pass, then follow the east ridge of Pearl to the summit. It appears there may be some challenge to that route along the ridge.
The route we suggest takes you off the road at tree line, then heads towards the two prominent north ridges that come off Pearl, taking a more direct route to Pearl. There are plenty of wildflowers to view in this north facing bowl and lots of skiing opportunities for back country skiers. Head for the westernmost of the two north running ridges and begin hiking up the ridge. It's possible to follow this ridge all the way up until it intersects the NW ridge of Pearl, but for some reason, we followed the ridge a short while, then dropped into the rock-filled gully between the two ridges. We continued up the gully until it intersected the NW ridge of Pearl at about 13,150 ft., then walked on SE to the summit amid a generous supply of rubble. This summit offers a commanding view in all directions. You can watch 4WD vehicles inching slowly along the road on either side of the pass. Also, some people connect Oyster, Pearl and Star into a single day, but the ridge connect to Star is very long.
Click thumbnail to view full-size photo + caption
Year Climbed: 2003
UN 13,312 (Oyster Peak) is sequenced with Pearl Mtn. for a nice, relatively short half-day hike if you have at least a stock 4WD that can make it to the intersection where the Pearl Pass Road and the road into the Conundrum/Castle Basin split off from each other. One way mileage and elevation gain for Oyster are measured from the summit of Pearl. Round-trip mileage and elevation gain assume completion of the entire sequence.
From the summit of Pearl Mountain, simply follow the connecting ridge NW over to Oyster Peak. The ridge first goes mostly north, then veers to the NW. If using our directions for Pearl, you'll likely be covering some ridge that you've already been on. There are some rockier sections that will be encountered but nothing that will push beyond basic Class 2 work. The most difficult section will be just beyond the Pearl-Oyster saddle. It took us well under an hour to make the nearly mile long traverse. The summit will afford a very close view of the infamous and extremely rugged south ridge of Castle with its numerous spires and cliffs. The ridge looks impossible.
For the descent, there are any number of ways to go down to the north. We took a fairly direct descent from just east of the summit, down a broad slope with shallow gullies which quickly became rocky, especially as we headed over a brief tundra bench area at 12,750 ft. and then down an even steeper slope that dropped us back into the broad basin at the north foot of the peak. Once back in this open basin, walk across tundra to rejoin your scent route and then head back to your vehicle.
Links to other information, routes & trip reports for this peak that may be helpful.
"Be easy to love, hard to break and impossible to forget." Anonymous