High Quality Content by WIKIPEDIA articles! The Driftless Area or Paleozoic Plateau is a region in the American Midwest noted mainly for its deeply carved river valleys. While primarily in southwestern Wisconsin, it includes areas of southeastern Minnesota, northeastern Iowa and extreme northwestern Illinois (see map at right). This region includes elevations ranging from 603 to 1,719 feet (184 to 524 m) and covers an area of 16,203 square miles (42,000 km2). This region`s peculiar terrain is due to its having escaped glaciation in the last glacial period.