Lock and Dam No. 10 is a lock and dam located in Guttenberg, Iowa on the Upper Mississippi River around river mile 615.0. It was constructed and placed in operation November 1937. The site underwent major rehabilitation 1989—2006. The dam consists of a concrete dam 763 feet (232.6 m) long with four roller gates and eight tainter gates. The earth embankment is 4,223 feet (1,287.2 m) long with a concrete spillway 1,200 feet (365.8 m) long.