The Panther Intaglio Effigy Mound in Fort Atkinson, Wisconsin, is a rare Native American archaeological site on the north side of the Rock River. Unlike the raised effigy mounds common in the upper Midwest, it is a man-made hollow shaped as an animal or spirit figure and is the only surviving reverse effigy mound in Wisconsin. Created sometime between about 700 and 1200 A.D., it is about 125 feet long and roughly two feet deep. Its meaning remains uncertain, though it has been identified as a lizard, panther, or water spirit. Preserved around 1910, it was listed on the National Register of Historic Places in 1970.