Fort Peck, Montana
|Courtesy Flickr/US Army Corps of Engineers
The Fort Peck Dam was a cornerstone project of the Works Progress Administration of Franklin D. Roosevelt's New Deal. It required the largest construction plant and workforce since the construction of the Panama Canal and peaked at 11,000 workers. It was the largest dam of any type in the world for over 30 years.
The record-setting, hydraulic-filled structure required the excavation of over 14 million cubic yards of earth, mixing it with water and then transporting it to the site. Its steel sheetpile foundations, installed to prevent water from seeping through the earth under the dam, extended to a record depth of 163 feet.