River Basin Surveys Papers, No. 31: Archeological Manifestations in the Toole County Section of the Tiber Reservoir Basin, Montana

The Tiber Dam, sometimes known as the Lower Marias Unit, had its inception some 50 years ago when William T. Cowan, State Senator from Hill County, Mont., stumped for the construction of a dam across the Marias River, the waters of the subsequent reservoir to be used for irrigation purposes. His was a far-sighted vision, one which was not fully appreciated until many years after his death. On September 30, 1952, President Harry S. Truman, before a crowd of 10,000 people, set off a blast marking the ground-breaking for the project. The dam, located 68 miles upstream from the confluence of the Marias and the Missouri Rivers, is a rolled earth-filled structure 4,300 feet long, with a maximum height of 205 feet and a maximum width at the base of 1,282 feet. The lake to be formed will have a surface area of 22,180 acres with a maximum length of 25 miles and
a maximum width of 4 miles.