From April through August for the past 19 years, mountain goats in Glacier National Park have been using specially designed passages under U.S. Highway 2 to get to a natural salt lick along the banks of the Middle Fork of the Flathead River.
After a 1979 avalanche destroyed a section of U.S. 2 near the salt lick, the Montana Department of Transportation used FHWA funds to build a goat passage under a new highway bridge and to adapt an existing bridge for safe goat passage. Goats were kept off the highway with a wall downhill and a fence uphill.
Security for goats crossing under the bridges was enhanced by fastening metal screening to the bridge rail and by planting 40 conifer trees. Existing goat trails were obliterated and new trails leading to the underpasses were dug. Visitors were accommodated - and the risk of human interference minimized - with an off-road overlook away from the underpasses.
Before and during road and bridge construction, workers went out of their way to protect the mountain goats from disturbances. They delayed construction until early August 1980 and limited it to certain hours of the day. They located construction away from key crossing zones. They restricted speed limits and stopped all passing vehicles for crossing goats. They sequenced construction activities so goats could gradually adapt.
Their extra effort paid off. Within weeks of construction, only a few crossing goats moved around the ends of the fence to cross the highway, and the goats seldom hesitated or ran back at the bridges or when they encountered visitors. Less than half showed signs of fear (erect tails).
In the first year, 99.4 percent of the crossing goats used the underpasses, and the number of individual lick visits doubled. Some goats even extended their visits to the lick into fall and winter. By 1984 all of the crossing goats used the underpasses.
[Photo: Underpass - Mountain goats used to cross U.S. 2 to get to a salt lick on the other side of the canyon. Now they can get there on rocky passageways underneath these bridges, shielded from view by tree cover and the steep hillside.]
Today, nearly 20 years after project completion, mountain goats continue to use the underpasses to cross U.S. 2 and enter the path to the salt lick.