Avalanche Slide, NPS photoTrees kncocked over by avalanche, NPS photo, G. MillerAvalanche chute, NPS photo

Avalanches are naturally occurring physical processes that cause disturbance to mountain ecosystems of the Crown of the Continent. As avalanches rip down mountain slopes they knock down trees and scour soils in their path transferring nutrients from high mountain ridges and catchments to valley bottoms.

The chutes created by avalanches can act as fuel breaks for fires that move laterally across mountain slopes, creating a more diverse landscape as regeneration of new plants takes hold. The extensive edges of these successional mosaics provide a diverse set of habitats for wildlife. Grizzly bears in the Crown are often seen foraging in the lush regrowth of avalanche chutes from spring through fall.

Of course, avalanches can be destructive as well. For wildlife species, such as elk and bighorn sheep, that use avalanche chutes in winter, avalanches can be a major source of mortality. Some avalanche paths are a threat to buildings, infrastructure, and human activities. Avalanche forecasters monitor the snowpack over the course of winter to evaluate changes in precipitation, temperature, humidity, cloud cover, wind speed and direction, and underlying terrain to aid in predicting avalanche events.