Follow that to its top, up the face above and eventually over a bulge to a wide ledge.
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By monitoring the trees we have direct evidence that this has worked.
The base of Yum Yum Yab Yum is notable by a slabbier streak of cleaner rock; a left-facing corner that starts about 20-25 feet up, and the pine tree on the belay ledge about 50 feet up.
Move up and right to old pitons.
P4 - Go up the inside of the open book for ~20 ft some trickiness to underneath the highest overhang above.