Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Unlikely
- Size
- 1–2
Today, low danger means that the odds are stacked in your favor, it is not a guarantee that you will beat the house. It is unlikely that you will trigger a persistent slab avalanche, but it is not impossible. Within the Grays River zone, snow depths vary widely between the Snake River Range, Salt River Range and Wyoming Range. As a rule, the Salt River Range has the deepest snowpack. In places where the December slab sits over weak, sugary November snow we continue to see propagation occur at that interface in pit results. Snow pits are only one piece of the puzzle though, and there has not been a reported avalanche in over two weeks. While unlikely, if you happen to find the shallow spot in the snowpack that triggers the avalanche, the resulting slide could be consequential given the shallow snowpack with rocks and stumps lurking just below the surface.
This problem is most likely to be found above 8,500’ on northwest through northeast aspects. Watch out for steep, rocky, unsupported slopes. Remember that you might find the trigger even after multiple people have ridden the same slope. Size up the slope before you ride it and consider what would happen if you triggered a small slab. Would it drag you through shallow rocks or into a terrain trap? Steer clear.
Continue to trench your sled track or dig into the snow to see if the weak structure exists where you are riding. Avoid terrain traps and consider consequences. Sheltered notherly slopes remain your best bet for good riding.
(12/14/2023)
SW of Sheep Pass: 10,000' SE aspect. Large avalanche that occured likely occured during our last storm cycle. Snowmobile tracks are present so hard saying whether it was remotely triggered or natural.
Photo: Alex Drinkard