From either viewpoint, start with the view west, back down the trail. Shuksan Arm, the ridge north of the trail, on the right, is held up by the oldest rocks in view, sedimentary rocks of the Chilliwack River terrane . Closer to the viewer on the same ridge, but up the slope to the northwest, a slab of chert was thrust over the sedimentary rocks along a fault. Blocks of the mangled recrystallized chert are scattered along the trail to Lake Ann in the basin to the west of this point. Look for white blocks made up of broken lenses and layers of quartz.
Some blocks look like weathered, coarsely-grained wood.
Mount Shuksan rises above the Curtis Glacier. Shuksan Greenschist overlying Darrington Phyllite and Bell Pass Melange along thrust faults. See diagram below. On Shuksan Arm,the mangled chert and shale are bound on the east by the Shuksan Thrust Fault which cuts across the ridge almost directly north of this view point. Above and east of the thrust is a slab of phyllite, overlain, going eastward, by the Shuksan Greenschist, which makes up the main bulk of Mount Shuksan.