Northern Highland

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!

Western Uplands

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