Spring Harbor Mound Group in Madison, Wisconsin, preserves two surviving Native American earthworks: a bear-shaped effigy mound on the grounds of Spring Harbor Middle School and a linear mound on nearby private property. Built by Late Woodland people between about 800 and 1100 A.D., they are the last remnants of a larger mound group first noted by white settlers in the late 19th century and later recorded in surveys as numbering between four and six mounds. By 1989, development had destroyed all but these two. Their listing on the National Register of Historic Places in 1991 recognized their age and their importance to the region’s effigy mound tradition.