The ten foot slab crux of the traverse, is well beyong "Class III" in my opinion due to the lack of hand and footholds, in combination with the steepness of the pitch making the smearing option a tough climbing move for all but the tallest climbers that can reach the upper edge of the slab with their hands.
I found an alternate way around this move, by heading east from the orange arrow about six feet and up a series of small solid rock shelves that I mantled and then proceeded aroung a small gendarme around the east side where passage to the top of the ten foot slab is gained thru a break in the ridge. This is still a serious "Class IV" move with significant exposure to the drop to Arapahoe Glacier well below. It is one of the hardest moves I would make when soloing (in dry conditions, only).
"After the first glass, you see things as you wish they were. After the second, you see things as they are not. Finally, you see things as they really are, which is the most horrible thing in the world."
--Oscar Wilde on Absinthe