Saint Anthony Falls

Saint Anthony Falls, or the Falls of Saint Anthony, located near downtown Minneapolis, Minnesota, was the only waterfall on the Mississippi River until it was replaced by a series of dams in the 1950s and 1960s. In the 17th century the falls became known to the world beyond the indigenous people who lived in their vicinity when they were observed by Father Louis Hennepin, who also brought the existence of Niagara Falls to the world's attention.

In the late 19th century the falls were in danger of collapse due to the weakness of the underlying structure. Dams were built above the falls and the surface of the falls was reinforced.

St. Anthony Falls was the upper limit of commercial navigation on the Mississippi until two dams and a series of locks were built between 1948 and 1963 by the United States Army Corps of Engineers. The locks make commercial navigation possible above Minneapolis but, since the locks in Minneapolis are smaller than most of the locks on the river, the practical limit for many commercial tows is a little downstream at St. Paul.

St. Anthony Falls locks and dams

Completed in 1963, the upper St. Anthony Falls dam is a horseshoe-shaped hydro-electric dam 93 feet (28 m) in height. The upper pool has a normal capacity of 3,150 acre feet (3,885,000 m³) and a normal level of 799 feet (244 m) above sea level.

Completed in 1956, the lower St. Anthony Falls dam is a gravity-type hydro-electric dam 60 feet (18 m) in height, consisting of a 275 foot (84 m) long concrete spillway with 4