Hydrogeology of the Rock River Watershed, Minnesota, and Associated Off-Channel Habitats of the Topeka Shiner

The Topeka shiner (Notropis Topeka) is a native species minnow that was once common in headwater streams of the Midwest and western prairie. The species is estimated to have had a wide range across several states but is now restricted to portions of these areas. The species is in decline in Kansas, Missouri, Nebraska, and Iowa. The Topeka shiner now exists in less than 10 percent of its historic geographic range in highly fragmented populations. The U.S. Fish and Wildlife Service (USFWS) listed the species as endangered on January 14, 1999. Recent studies in Minnesota have shown that relatively abundant populations appear to be surviving across much of the southwestern portion of the State in the Big Sioux watershed.