A tiny land snail, the Iowa Pleistocene snail, is smaller than a shirt button, at about 5 millimeters (1/4 inch) in diameter. Considered a glacial relict species, it has survived only on these small areas where temperature, moisture and food are suitable. The snail seeks cool, rocky slopes near coldwater streams, cliffs, valleys, and sinkholes.
Because of the fragile nature of the habitat and the small size of the total population, this snail was placed on the federal endangered species list. The primary recovery option for the tiny snail is permanent protection of remaining colonies. Thirty-six known colonies are currently in northeast Iowa with one population occurring in northwest Illinois.
The areas inhabited by this snail are closed to the public to protect this endangered species and its rare habitat.