Quake Lake - Hebgen Dam and Creation of The Lake

Hebgen Dam and Creation of The Lake

Hebgen Dam, built in 1917, is a concrete core and rock fill faced structure that sustained severe damage but continued to hold. Repairs were completed on the dam spillway in a few weeks. The landslide, which occurred downstream from the dam, blocked almost all the flow of the Madison River which began to fill in the void upstream from the slide. In less than a month, the waters had created what is now known as Quake Lake. The lack of a reliable water outlet for this new lake forced one of the largest mobilizations of the U.S. Army Corps of Engineers ever commenced in the western U.S. Before the new landslide was breached by the quickly rising waters, a spillway was constructed to ensure erosion and potential failure of the natural dam would be minimized.