Ocooch Mountains are a place name for the Western Upland area of Wisconsin also known as the Driftless Region, meaning un-glaciated, lacking glacial drift or the Paleozoic Plateau, referring to a geologic era, Greek for "ancient life". The lack of glaciated terrain accounts for high hills, bluffs, and ridges. The Chippewa, Black, La Crosse, Kickapoo, Baraboo, Lemonweir, Pine, Wisconsin, Grant, Platte and Pecatonia rivers and their tributaries create deeply eroded valleys that contrast the nearby peaks. One dramatic example is Wildcat Mountain State Park. The Baraboo Range anchors the eastern edge where the Wisconsin River turns and runs through the area to the Mississippi River. The Baraboo Range is a monadnock in Sauk County and a National Natural Landmark formed 1.6 billion years ago fea