In 1976, the upstream Teton Dam failed during filling, causing spring snowmelt to race downstream into the Teton River, a tributary of the Snake, demolishing several towns along its path. In an attempt to contain this flood, water was released from American Falls Dam as quickly as possible. If the dam were to fail, the other Snake River dams would experience a flood they were not designed to cope with, although the lower Columbia River dams would most likely survive. The American Falls reservoir filled, but its level did not even rise to its spillway crest.