Driftless Area National Wildlife Refuge is a United States National Wildlife Refuge in northeastern Iowa, southwestern Wisconsin and northwestern Illinois. It is a non-contiguous collection of parcels in the vicinity of the Upper Mississippi River National Wildlife and Fish Refuge. The refuge was established in 1989 to help the recovery of two federally listed species: the endangered Iowa Pleistocene Snail and threatened plant Northern Wild Monkshood. Although the refuge was established to protect the snail and flower, an entire rare community of plants and animals is preserved on these sites. The U.S. Fish and Wildlife Service manages the refuge as part of the National Wildlife Refuge system. Currently, the refuge consists of nine sites totaling in four counties of Iowa only. In descending order of land area they are Clayton, Dubuque, Jackson, and Allamakee counties. Geology Portions of Iowa, Wisconsin, Minnesota and Illinois contain unusual geology. The karst region, referred to as the "Driftless Area", escaped the last glaciers leaving the Paleozoic-age bedrock subject to erosion. In addition to the curious topography of steep slopes and cliffs, there are unique habitats. Certain slopes, usually north facing, are covered with a talus layer that allows ice-cooled air to exit from underground cracks and fissures. Upland sinkholes contribute to the air flow regime and are an important component of a unique system called an algific talus slopes, meaning a cold producing rocky slope. Even on a midsummer day when the outside air temperature is 90 °F (32 °C), ground temperatures on these slopes range from 42 °F (6 °C) to about 55 °F (13 °C). Although the slopes will freeze in winter, the temperatures are moderated. These slopes remain cool throughout the year and are home to rare species of plants and animals. Chilled air In the summer, air is drawn down through sinkholes, flows over very cold groundwater and is released out vents on the slopes. Summer temperatures on the slopes range from to . In winter, the air is drawn into the vents, and the groundwater again freezes. Because of the cool temperatures and moist conditions, unusual plants for this part of the country grow on the slopes. Typically growing in a colder more northern climate, yews, balsam fir, Showy lady's slipper and golden saxifrage can be found on the cool slopes. These cold microclimates of the slopes allow the rare plants and animals to survive. Fossil snail A tiny