Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Don't go to sleep on this snowpack. Put plenty of space between you and steep open slopes on the north side of the compass. From late February through the first few days of March, multiple very large and widely propagating avalanches were reported. In two separate involvements near Harts Pass, riders were buried and in one incident, one person was killed.
The January Drought Layer is about 3 feet below the surface near and east of Washington Pass. This layer is deeper further west of Washington Pass and may be more difficult to trigger. Aside from the widespread recent avalanches, you may not see other signs of instability.
Avalanches may need a larger trigger like a snowmobile or cornice to impact deeper layers. These avalanches could break across entire slopes, run long distances, and even reach valley bottoms. The only way to deal with this issue is to be diligent and avoid this terrain.
(2/28/2025)
A large avalanche near Hart's Pass that caught 2 snowmobilers and resulted in one fatality on February 28th.
HS-AM-D2.5-R4-O. Cone Mtn, NE, 6,800ft
Photo: NCH