Flandrau State Park occupies a steep river valley along the Cottonwood River beside New Ulm, preserving marshy oxbow lakes, forested slopes, and river habitat within a developed area. Created in 1934 as Cottonwood River State Park during the Great Depression, it was built by Works Progress Administration and Civilian Conservation Corps crews, whose dam formed a reservoir before repeated flood damage led to its removal in 1995. The park is especially notable for its New Deal-era rustic buildings, designed by Edward W. Barber with influences from New Ulm’s German heritage. During World War II, its former camp housed about 160 German prisoners of war. Renamed in 1945, it honors Charles Eugene Flandrau.