The Driftless Area includes 15,425,920 acres,which is 24,103 square miles, covering all or part of 57 counties in southeast Minnesota, southwest Wisconsin, northeast Iowa and a small portion of northwest Illinois in the Upper Mississippi River Basin. This unique area was by-passed by the last continental glacier resulting in a steep, rugged landscape. The area is characterized by karst topography with shallow limestone bedrock, caves and sinkholes.

The land, soils and ecosystems in the area are diverse and include many threatened and endangered species. The Driftless Area, also known as the Paleozoic Plateau, drains into priority streams and rivers before emptying into the Upper Mississippi River. These water courses, which include many cold water trout streams, are recognized on state and national levels for their economic and environmental importance.