The Impact of Mountain Goat Migration on Unconsolidated Slopes in Glacier National Park, Montana

Native mountain goats must cross U.S. Highway 2 in order to gain access to a natural salt lick along the southern boundary of Glacier National Park, Montana. Prior to 1981, goats approached through forest cover and then crossed over the highway. Reconstruction of the highway incorporated two goat underpasses which substantially altered the migration pattern. Large numbers of goats now utilize an open, south-facing slope, and cause extensive erosion. Repeat photography illustrates the extent of erosion over the period since 1981 , and provides estimates of the amount of sediment removed. Erosion rates are startlingly high, and are a direct result of well-meaning human interference associated with construction of the goat underpasses.