OverviewThis is probably the most straightforward legal route to the summit of Castle Peak, and involves some 3rd and possibly 4th class scrambling, depending on your exact route. The approach is largely on trail, with some bushwhacking likely needed closer to the summit towers. The route covers approximately 6.5 miles roundtrip, approximately 2200' of total gain, and takes 5 hours total at a moderate pace.
Overall, the latter half of the climb is characterized by losing, and then just as suddenly finding trail segments. Study your topo beforehand and have a decent idea where you're going, and you should be fine.
Getting ThereSee approach route description on the main page.
Route DescriptionFrom the parking area, cross through an opening in the fence and follow the faint, yet obvious trail generally uphill and to the SW. The trail eventually enters a narrow grassy valley in the trees before reaching a partially open area with a large gray dirt slope on the right. Here, turn left and pick up the continuation of the trail as it passes through several scenic open meadows. The summit towers of Castle Peak will be occasionally visible as you gain elevation.
Next, gain the ridge to your left wherever you see fit. There are at least 3 semi-obvious dirt paths leading from the valley to the crest of the ridge, or if these cannot be found, simply bushwhack up. The ridge crest is initially pleasant, but after a steep climb up a meadow, the forest becomes thicker and filled with deadfall. Continue picking your way through this mess. Your goal is to reach the lower edge of a talus field just south of the summit towers, at approximately 39 46.278 N, 106 49.862 W.
At the weakness, you have two options: go left, which entails some 4th class climbing, loose rocks and boulders, and at least one awkward move necessitating pulling yourself up. Or, go right on gravel-covered but otherwise very climbable 3rd class ledges. Both options reconvene perhaps 20' above the base of the cliffs, from which the most obvious path upward and to the right will lead you to the ridge crest, immediately east of Tower 3.
From here, drop down the other side of the ridge on a surprisingly wide and unexposed ledge, bypassing a few initial rocky fins to the north. You should see an obvious weakness in the rock, where a large metal cable is hanging down. Scramble up the 3rd class ledges here to the crest of the ridge, turn left, and make the final few easy moves to the unexpectedly-large, flat, grassy summit area. Watch out for the broken glass, relax, and enjoy the views.
Essential GearA helmet would be advised, due to potentially loose rock on the last portion of the route. Climbing gear if attempting the other towers. Trekking poles are useful for the bushwhacking toward the end of the route.
Otherwise, standard hiking gear.