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 Saint Croix in Wisconsin 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) |