Paleontology and geology
During the Quaternary, massive glacial ice sheets influenced North America. Nowhere are their effects more striking than in Wisconsin. In fact, the final glacial advances (100,000–10,000 years ago) were named the Wisconsinan due to the state’s classic glacial landforms. Glaciers deposited large boulders called erratics, created drumlins, gouged bedrock, carved the valley of the Wisconsin Dells in central Wisconsin, and formed the scenic landscapes composed of moraines, eskers, and kettle lakes. Animals adapted to a cold climate, such as the wooly mammoth, large beavers, and horses, inhabited Wisconsin’s forests of spruce and hemlock. Fossils of seal, walrus, and whale are found along the Great Lakes.