I used the familiar Herman's Gulch trail to approach Pettingell, then went to the right of the lake and up to the long ridge that approaches the peak from the east. This allows for some challenging class 3 ridge scrambling, made even more exciting with a fair amount of snow up high. The route is fairly obvious from Herman Lake.
The trail to Herman lake was well packed the first 1-1.5 miles, I used no traction or flotation. From that point I was breaking trail in snowshoes to Herman lake, which is about 3.5 miles from the start. Once I started ascending from Herman lake, I used no traction or flotation, between exposed rocks and fairly soft snow, it wasn't really necessary. Once you turn left and get to the long ridge, there are some difficult sections to get around. I stayed as close to the ridge proper as possible, but it wasn't always possible, and I had a few class 4 moves to simplify the route. Fun route, and nice views from the summit. I descended the standard "south slopes" route, it was much easier and shorter than the east ridge.
Photos (click for slideshow):