FATMAP by Strava

Castle Peak - South Face

Sun Valley

A notoriously remote mountain of the Fifty Classic Ski Descents, buried in Idaho’s White Clouds Wilderness.

Ski Touring Severe

17 km
1.6 km
1.6 km
1 day +
Low Point
2.7 km
High Point
3.6 km
Castle Peak - South Face Map

Castle Peak is an impressive mountain in the White Clouds Wilderness of Idaho. The South Face is listed in the Fifty Classic ski descents of North America, but without much information. What’s described here is just one possibility for approaching and skiing the mountain, and it’s only an approximation of the route. This track begins from Fourth of July trailhead, which is several miles from road access in the winter. You’ll want a snowmachine to get in, and you can likely cut off more of the route by riding all the way to Washington Lake.


From the south end of Washington Lake you’ll find the widest gully in the ridge above, and boot up it. This will be the first major gauge of snow conditions, as this gully itself can present hazards. Once on top, you’ll enjoy your first view of Castle Peak––and it’s quite the view. Dead ahead are the striking couloirs of Castle’s ragged SW face, though the S-face line remains out of sight. From there you’ll get a few hundred feet of descent into Chamberlain Basin. Continue across a lake and go over a forested knoll, then you can begin to traverse the south slope of Castle. You may choose to go lower and give wider berth, depending on the look of the chutes above.

The final test for conditions comes at the base of the south face, where you’ll stare straight up a massive, yawning gully. It forks into other couloirs and feeder chutes that could be explored, but the route mapped here goes straight up the gut of it. There is one notable couloir about ⅔ of the way to the top that is often skied instead of the main gully, however, so take your pick. Top out on the ridge, if not the actual summit, and find stupefying views down the precipitous north face. Then turn and enjoy your hard-earned Fifty Classic descent!

Sources: https://noahhowell.com/2019/10/30/castle-peak-id/ http://idahoalpinezone.com/index.php?p=292 http://mt-adventures.blogspot.com/2015/02/white-cloud-mountains-castle-peak.html



Steep skiing at 38-45 degrees. This requires very good technique and the risk of falling has serious consequences.

Medium Exposure (E2)

2 out of 4

As well as the slope itself, there are some obstacles (such as rock outcrops) which could aggravate injury.


4 out of 4

In the high mountains or remote conditions, all individuals must be completely autonomous in every situation.

Best time to visit

between January and May


  • Face
  • Alpine
  • Couloir
  • Ski Mountaineering

Equipment required

  • Skins
  • Ice axe
  • Crampons