Geographic snapshot on how the region came to be
The River Falls area is considered part of the Western Upland, which stretches from St. Croix County in the north to the state border with Illinois in the south.
It's a rugged, hilly region deeply dissected by rivers and streams. The area is characterized by rocky outcroppings and numerous small caves, as well as sharp and frequent changes in altitude. Elevation can range from about 600 feet above sea level in the Mississippi River Valley to more than 1,200 feet above sea level in many of the ridges.
The Mississippi, Chippewa and other rivers carve deep gorges through the upland.
Even surrounding small creeks and streams have coulees penetrating some two to three hundred feet deeper than the surrounding land.
Before the last ice age, most of the land in the northern United States was similar to the land of today's Western Upland, with rugged ridges and valleys. But as glaciers came to cover the continent, they toppled the ridges and filled in the valleys, creating smooth plains. The Western Upland of Wisconsin is part of the Driftless Area, a region that has avoided being covered by glaciers for the past several million years. This explains why the region has retained its rugged landscape.
Farmland is prevalent in the Western Upland anywhere where the slope of the land is gradual enough to permit it, generally on the ridge tops and the valley bottoms. Both fields and pastureland are common in the region. The hillsides and narrow ravines that are unsuitable for agriculture are covered in forests. Oak, hickory, maple, and birch trees dominate the woodlands.
The St. Croix is an important river in the Driftless Area, as it was the outlet for Glacial Lake Duluth, forerunner to Lake Superior, when the eastern outlet was blocked by the continental ice sheet. These rivers all have deep, dramatic canyons giving testimony to the immense quantity of water which once surged through them.
Karst topography is found throughout the Driftless. This is characterized by caves and cave systems, disappearing streams, blind valleys, underground streams, sinkholes, springs, cold springs and cold streams. Disappearing streams are when surface waters sinks down into the earth through fractured bedrock, either joining an aquifer, or becoming an underground stream.
Blind valleys are formed by disappearing streams and lack an outlet to any other stream. Sinkholes are the result of the collapse of the roof of a cave, and surface water can flow directly into them. Disappearing streams can re-emerge as often powerful springs, often having been cooled down by the water's journey through the earth.
Cold streams with cold springs as it sources are noted as superb trout habitat.
Goat prairies, sometimes termed hill prairies, or dry prairies are also found mainly along the valley of the Upper Mississippi River in the Driftless Area, but can occur elsewhere. (Wikipedia)