highest summits provides summiteers with an expansive view of the northern Sierra, which on clear days includes distant Lassen Peak in the north and the coastal hills to the west.
Best Time
Mid-July–early September is the prime time for an ascent. Though this is a favorite winter ascent of backcountry skiers and snowshoers, most of the lingering snowbanks across the trail have disappeared by mid-July.
Finding the Trail
West of Donner Summit, take the Castle Peak/Boreal Ridge Road exit from I-80. Drive to the frontage road on the south side of the freeway and proceed east 0.3 mile to the Pacific Crest Trail (PCT) parking area. The large parking lot has trailer parking, pit toilets, and running water in season.
Logistics
Two alternatives will shorten the trip. The first option is to park near the start of the Castle Valley Road, just north of the I-80 ramps, and walk the road to Castle Pass. With a high-clearance vehicle, the second option is to drive the Castle Valley Road to a parking area near the Hole in the Ground Trailhead. From there a shorter hike along the road leads to Castle Pass.
Trail Description
Head north on the PCT around the fringe of the meadow and pass through a pair of large culverts, underneath the eastbound and westbound lanes of I-80. Beyond the culverts you make a moderate climb to the crossing of a seasonal creek and then come to a well-signed, four-way junction, 1 mile from the trailhead.
Remaining on the Pacific Crest Trail, you proceed straight ahead at the four-way junction, following signed directions to Castle Pass. The PCT rises and then drops to the north shore of a small pond, where you should veer right at an unmarked Y-junction with a path bound for the Donner Summit Rest Area.
Cross-Country Routes
Ambitious peak baggers can double summit by following a boot-beaten path from Castle Peak along the north ridge to the top of 9,017-foot Basin Peak. On the way back, dropping west from the ridge about halfway between Castle and Basin Peaks to head cross-country to a connection with the Pacific Crest Trail in Round Valley provides an easier alternative to a return over Castle Peak.
Beyond the unmarked junction, you follow mildly graded trail through mixed forest, toward Castle Valley. Eventually the trail brings you alongside the creek for a brief time and then travels just east of the verdant meadows of Castle Valley. Use trails branch away from the PCT at various points, headed toward the creek and meadows. At 2.3 miles from the trailhead you cross a well-traveled dirt road, and then continue upstream through Castle Valley, hopping over lushly lined tributaries along the way. Nearing the head of the valley, the PCT bends to the west on an ascending traverse to a signed three-way junction with a trail from the Castle Valley Road.
At Castle Pass take the use trail to the right, which ascends the west ridge of Castle Peak. As you climb the rocky ridge the conifers diminish, allowing you increasingly good views of Castle Peak ahead and other peaks and landmarks scattered around the Donner Pass region. A steep, zigzagging ascent heads around to the north side of the mountain, where switchbacks then lead you toward the summit. After a rocky stretch of climbing, a splendid view greets you at the top of the 9,103-foot peak.
Castle Peak
Start at Pacific Crest Trail Trailhead
Veer right at Glacier Meadow Loop junction
Veer right again at Glacier Meadow Loop junction
Turn left (north) at PCT junction
Proceed straight ahead (west) at Summit Lake Trail junction
