The flood waters traveled west along the route of the Henrys Fork of the Snake River, around both sides of the Menan Buttes, significantly damaging the community of Roberts. The city of Idaho Falls, even further down on the flood plain, had time to prepare. At the older American Falls Dam downstream, engineers increased discharge by less than 5% before the flood arrived. That dam held and the flood was effectively over, but tens of thousands of acres of land near the river were stripped of fertile topsoil.