Landslides Along the Lewis Overthrust Fault, Glacier National Park, Montana

As development in the mountainous areas of the western United States continues to accelerate, the exposure of humans and structures to natural hazard threats from high-magnitude masswasting events also increases. This encroachment into previously uninhabited, undeveloped mountain areas creates situations whereby mass-wasting events now pose threats to human activity. Glacier National Park, Montana, is one such location where the potential exists for high-magnitude mass-wasting events. The mountains in this area commonly have steep slopes, high relief, and weathered bedrock features. These features, combined with a mid-latitude climate conducive to extensive frostweathering action, have resulted in a landscape possessing many slope movement deposits. Mass-wasting features such as slumps, rockslides, rockfalls, earthflows, and talus slopes are common along the slopes of the mountains. Along one area in the Park in particular, the Lewis Overthrust Fault along the eastern front of the Rockies, extensive mass-wasting deposits are found.