Some whumpfing while skinning above steep east aspects around 1700 m in the Flatiron bowl. Could feel a crust under 30-50 cm powder on small, steep-sided knolls along the ridge. No other instabilities observed. Ski pen ranged from 0 cm on wind affected sections of the ridge to 30-40 cm in the bowl. Skiing back down the ridge through the trees was well filled in.