In northeast Iowa, cliffs formed of ancient limestone are riddled with sinkholes, caverns, groundwater springs and algific talus slopes (also known as cold-air slopes). The glaciers of the last Ice Age left this region untouched. Because of their unique geology, these hillsides remain cold even on the hottest days and contain plants and animals found during glacial periods 10,000 years ago.
The Iowa Pleistocene snail, once thought to be extinct, was rediscovered here in 1980. Besides the Iowa Pleistocene snail, many other land snails make their homes on these slopes, including eight additional species that have been proposed for endangered species status. The area also is home to 96 percent of the entire population of the federally-threatened northern monkshood plant. Thick layers of mosses, ferns and liverworts can be found on the coldest portions of the slopes, along with yellow and paper birch, mountain maple, yew and balsam fir. Due to the ruggedness of the landscape, which has made development difficult, this region also has some of Iowa’s highest quality forest remnants and freshwater streams.
Many activities threaten the sensitive slopes including inappropriate grazing and logging practices and trash dumping. The Conservancy owns 400 acres here and helped establish the Driftless Area National Wildlife Refuge to preserve the rare landscapes and species of Iowa’s driftless area. To save this area the Conservancy is working with U.S. Fish and Wildlife Service, Iowa Department of Natural Resources, county conservation boards and private landowners to protect the rare slopes.
The long-term plan is to conserve sufficient algific talus slope sites to ensure the viability of Iowa Pleistocene snail and northern monkshood plant.