Road observations from Hwy 2
By the looks of the debris and into the crown it looks like this failed on deeper persistent weak layers. Could have failed initially an upper layer (buried surface hoar) and in some locations at least, it appears to have stepped down to the basal facets. Crown thickness likely also varies due to wind-loading.
The debris and crown makes me think this was more of a soft slab type and failed on the buried surface hoar and/or NSF buried on New Years. But visibilty was pretty poor so more uncertain about this avalanche.
Forecast Hotline: 406.257.8402
Call or text an observation: 406.66AVYOB