Michigan Sea Grant , University of Michigan and Michigan State University, Bugwood.org

US Fish and Wildlife Service - Michigan Sea Grant , Michigan Sea Grant, Bugwood.org

United States Geological Survey (USGS) , US Geological Survey, Bugwood.org

Minnesota Department of Natural Resources - FIA , Minnesota Department of Natural Resources, Bugwood.org

South Dakota Game, Fish and Parks , Bugwood.org

United States Geological Survey (USGS) , US Geological Survey, Bugwood.org