6 is a lock and dam located near Trempealeau, Wisconsin on the Upper Mississippi River near river mile 714.1.

It was constructed and placed in operation in June 1936.

The dam consists of 893 feet (272.2 m) long concrete structure with five roller gates and 10 tainter gates.

Its earth embankment is 2,600 feet (792.5 m)long and the concrete overflow spillway is 1,000 feet (304.8 m) long.

The lock and dam are owned and operated by the St. Paul District of the United States Army Corps of Engineers-Mississippi Valley Division.