Our party decided to ski The Thumb on Sunday via a route that followed the Birch Lake summer trail to avoid exposure.
We reached the snowline at the Birch Lake Trailhead (6,600') and transitioned to skins. There was a refreeze overnight and travel was fast in the early morning hours. The snow began to warm up as we began climbing the final ~2,500' from Birch Lake to The Thumb. We reached the summit at 12:20 and began our descent at 12:50.
The SE aspect near the summit had turned to corn and made for excellent skiing. As we skied back down into the Birch Lake we began to see roller balls forming on the steeper NE and E aspects within the upper drainage. We stuck to the low angle slopes north of Birch Creek on our descent to avoid terrain traps. SE and S aspects had transitioned to a consolidated spring snowpack and offered great corn skiing. N and NE facing slopes were still transitioning from more midwinter like conditions.
As we reached McMurray Meadows we saw three D2/D3 size wet loose slides on the east gullies of Birch Mountain that had not been there when we passed earlier in the morning.