Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
A mix of depth hoar, facets, and faceted crusts buried 2 to 3 feet deep are reactive to human and remote triggers. Northerly and easterly facing terrain near and above treeline has been most active due to thicker slabs over well-developed weak layers. The lower half of the snowpack is highly variable, shaped by early-season droughts, record-warm temperatures, rain, and past extreme wind events. As a result, expect inconsistent feedback as you move across aspects, elevations, or even different parts of the same slope. Cracking and collapsing are obvious signs of instability, although your first clear signal could be a dangerous avalanche. The most reliable way to manage this problem is by choosing slopes less than 30 degrees. Wind-eroded terrain, lower elevation southerly slopes, and elevations below ~10,000' offer less risky options, where slabs are less common and weak layers are often capped by stronger crusts.
A large, remotely triggered avalanche broke on weak layers near the ground on Monday above West Brush Creek. (1/6/2026) Photo: Crested Butte Avalanche Center