- Where to Go
- The Best of Milwaukee and Madison
- The Best Wisconsin Weekends
- A Perfect Week in Door County
- Wisconsin for Recreationists
- Rustic Road Tripping
- Made in Milwaukee
- Madison Weekend
- Sports: The Packers and Beyond
- Out on the Town in Milwaukee
- Say Cheese!
- Four Days in the Mad City
- A Wisconsin Family Road Trip
- Wisconsin’s Best Brews
Wisconsin was once at the earth’s equatorial belt buckle. Plate shifting created the Canadian Shield, which includes about two-thirds of eastern Canada along with Wisconsin, Minnesota, Michigan, and New York. A half billion years ago, a glacial lake flooded the Wisconsin range—the northern section of present-day Wisconsin.
Glaciation during the two million years of the four glacial periods—geologically, a blink of an eye—is responsible for Wisconsin’s one-of-a-kind topography. (The final advance, occurring 70,000–10,000 years ago, was even named the Wisconsin period.) Wisconsin endured five glacial “lobes” penetrating the state, reducing the state’s previous ambitious heights to knobs and slate-flat lands and establishing riverways and streambeds. Only the southwestern lower third of the state escaped the glaciers’ penetration, resulting in the world’s largest area surrounded completely by glacial drift.
Covering 15,000 square miles, the Canadian Shield is the most salient physiogeographical feature of northern Wisconsin. Underlain by crystalline rock on a peneplain, the bedrock and glacial soils are particularly suited to growing timber.
More: Its high concentration of lakes is what separates the region from the rest of the Midwest—and, in fact, distinguishes it in the world, since only the remotest parts of Quebec and Finland have more lakes per square mile.
Lake Superior Lowlands
Wisconsin’s northern cap along Lake Superior displays a geological oddity, unique in the Great Lakes—a fallen trench of Lake Superior, flanked by palisades. Before the glaciers arrived to finish carving, shifting lowered this 10- to 20-mile-wide belt (now a half mile lower than the surrounding land). This wedge-shaped red-clay plain consists mainly of copper-hued outcroppings and numerous streams and rivers and waterfalls.
Eastern Ridges and Lowlands
Bordered by Lake Michigan on the east and north, this 14,000-square-mile region was much richer in glacial deposits, and the fecund soils attracted the first immigrant farmers. The impeded waterways were ideal conduits for floating timber to mills.
The Kettle Moraine region southeast of Lake Winnebago is a physical textbook of glacial geology.
Central (Sand) Plain
Bisected by the mighty Wisconsin River, the crescent-shaped Central Plain region spreads for 13,000 square miles. Once the bottom of enormous glacial Lake Wisconsin, the region is most noted for its oddball topography of sand dune-esque stretches mingled with peat bog, cranberry marsh, buttes and outliers (younger hoodoo-shaped oddities) and jack pine and scrub oak—all made famous by Aldo Leopold’s A Sand County Almanac. The central section of this region is relatively flat, but the lower third contains buttes and outliers (younger rock formations). All this at the Wisconsin Dells!
The Western Uplands region subsumes the radical Driftless Area. Geologically the roughest and wildest sector of Wisconsin, it contains rises up to 400 feet higher than the contiguous Central Plain. The unglaciated plateau experienced much stream erosion, and the result is an amazing chocolate-drop topography of rolling hillock and valley—with the odd plateau and ridges not unlike West Virginia—capped by hard rock and sluiced by the lower Wisconsin and Mississippi Rivers.
© Thomas Huhti from Moon Wisconsin, 5th Edition