Lock & Dam 4

  • Located on Mississippi River mile 752.8 in Alma, Wisconsin.
  • Constructed and placed in operation in May, 1935. Last major rehabilitation completed from 1988 to 1994.
  • Dam consists of a concrete structure 367 feet long with six roller gates and 22 tainter gates. Earth embankment 5,400 feet long.
  • Lock is 110 feet wide by 600 feet long.
  • Brochure

Recreation Opportunities

The observation deck is currently open during daylight hours.

Lock and Dam 4
Lock & Dam 4, Alma, Wis.

Contact Information

U.S. Army Corps of Engineers
St. Paul District
Lock and Dam No. 4

P.O. Box 325
Alma, WI 54610-4421

(608) 685-4421