Outside the Classroom - The Bluffs of Juneau County
One of the unique pleasures of Juneau County is the bluffs that spread throughout the county as well as most of western and southwestern Wisconsin. Juneau County is in the driftless area of Wisconsin, and the bluffs were a result of the most recent glacier which happened approximately over 10 thousand years ago.
The glaciers came through Wisconsin from the north and northeast and while moving in a south-southwestern direction, the Laurentide Ice Sheet had blocked the Wisconsin River near Wisconsin Dells. As a result, the water spread across and completely submerged Adams and Juneau Counties as well as a few others. The enormous lake remained for about five to ten thousand years. When the ice sheet regressed, so did the lake. The bluffs that stood tall looking like mesas and buttes, ended up being islands above the water within a glacial lake. The waves from the lake caused erosion on the sides of the rock formations. Most of the rock on the surface are from the Cambrian Geologic Age and are primarily sandstone and dolomite with some shale. Some less abundant rock types include gneiss, migmatite, and amphibolite Weathering and erosion tend to break off rocks from the bluffs in vertical fragments and causing other structural changes. According to the Wisconsin Department of National Resources, some rocks and boulders made up of different compositions than the bedrock are called erractics. They are boulders that were embedded in icebergs which floated and lodged against the mesa and buttes. When the ice melted, the boulders remained lodged on the sandy flanks of the bluffs.
Most of the bluffs were formed when the glaciers pushed the land southwest. This area was untouched by the ice sheets or was on the far west side of the Green Bay lobe. The numerous lakes and wetlands that pepper the northern and eastern parts of Wisconsin are a direct result of the last glacier.
Most of the bluffs in Juneau County have been given names for various reasons. One example is Target Bluff located in Camp Douglas. This bluff was given its name during the 1850s when the railroad was being constructed. Builders gave the bluff its name because they used it as a target to mark their location. Target Bluff was the namesake for the former German Haus Restaurant located at the east side of the base of the bluff.
Mile Bluff—also the name of the Medical Center in Mauston—was given its name because of the length of that rock formation. The highest elevation in Juneau County is Johnson Hill which stretches between Hwys 80 and 82 in Plymouth Township. Its summit ranges between 1380-1400 feet, depending on the resource one uses.
There are nine Ice Age National Scientific Reserves throughout Wisconsin. Devil’s Lake State Park is one of them, but the closest is Mill Bluff State Park, northwest of Camp Douglas. The Reserve was established in 1964 to protect the unique glacial landforms in Wisconsin. Because these are protected, it is illegal to vandalize any of the bluffs, and if caught, would be subject to a heavy fine.