&quot;&quot;Spirit Island with Stone Arch Bridge in background. From Minnesota Historical Society 5/27/1899 -- Spirit Island once stood downstream of the falls. Bald eagles often nested in its trees. The island held special significance for the Dakota who believed the spirit of a woman and child lived on the island. The woman, Dark Day, was angry because her husband took a second wife. When her tribe landed to portage around the falls, she propped her baby up in the canoe and continued to paddle towards the falls. Ignoring the frantic calls of her husband and tribe, she sang to her child and paddled over the falls, vanishing into the mists below. The Dakota never recovered their bodies and believed the spirits of the mother and child came to the island downstream of the falls. The island became known as Spirit Island and it was said that at times the voice of the mother singing to her child can still be heard over the roar of the rushing water. Europeans saw the island in a different light. Noticing that much of the island had large deposit of Platteville limestone, they quarried it away and used the limestone to build their mills. The Army Corps of Engineers eventually removed the rest of Spirit Island when they installed the lock next to the falls.&quot;&quot; 
Above statements and photo from webpage: 
http://www.geo.umn.edu/courses/1001/1001_kirkby/SAFL/WEBSITEPAGES/11.html