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The Northern Highland of Wisconsin
The Northern Highland The Lost Mountains of WisconsinFar back in the geological past, perhaps six or seven hundred million years ago, Wisconsin was part of a mountainous region which covered all this state and much territory outside it. It had peaks and ridges similar to those in the Alps. We know of this former mountainous condition from a study of the rocks and the topography of today.
Remnants of rock folds reveal that there were once lofty ridges and deep valleys in northern Wisconsin. The types of the folds tell us that the ridges were parts of a mountain range more like the Alps or the Rockies than the Appalachians. The granites show that erosion has cut down to igneous rocks such as are formed only by deep- seated cooling of molten intrusives, often beneath the arch of a lofty mountain range. The gneisses and schists suggest the former presence of tremendous pressure and some heat. The trap rocks indicate that lava flows emerged at the surface in the later stages of the mountain history. The fossils in the overlying sedimentary rocks show that these mountains are among the oldest in the world.
These lofty mountains were attacked by weather, wind, and streams, by solution underground, by plants and animals at the surface, as mountains are being attacked today. They were gradually worn down, till nothing remained but a low, undulating plain with occasional hills. This we call a peneplain.
The destruction of the mountains took a long time, of course, but time enough was available. The rivers carried sand and mud and dissolved mineral matter from the mountains into the sea. There it was deposited as sandstone, shale and limestone. The mountains were uplifted again and worn down again, repeating this history several times.
Eventually, Wisconsin and the adjacent region sank beneath the ocean, probably remaining submerged for long ages. While it was sinking, the hills that rose above the surface of the peneplain may have been little islands in the sea for a short time. Waves may have beaten against their shores, making beaches. Subsequently it was uplifted and submerged several times.
Two hundred million years or so ago this part of the United States was uplifted for the last time, and has since remained dry land. The peneplain on the site of the ancient lofty mountains of Wisconsin was completely hidden beneath the limestones and sandstones.
The work of weather and streams recommenced, and continued till the state was fashioned into something similar to its present form. Throughout all parts of Wisconsin except the Northern Highland, the Baraboo Range, the Barron Hills and such places, the worn- down pre- Cambrian mountains lie deep beneath the present surface. In the northern part of Wisconsin the worn down mountains have been revealed. We know the visible portion of these worn- down, buried and exhumed mountains as the Northern Highland of Wisconsin.
Topography of the Northern Highland
The Northern Highland belongs to a great upland area that stretches northward in Canada to Labrador and Hudson Bay. It has a strong southward slope and, as the highland is shield- shaped and gently arches, it also has east and west components of slope. The slant of a medial line from the northern to the southern border is less than six feet to the mile.
A portion of this highland in Marathon County, near the village of Marathon, is typical of the whole. It lies in the Driftless Area and therefore represents a portion of the highland not at all modified by glacial erosion and deposition, but shaped entirely by weathering and stream erosion.
This is a moderately hilly region, the tops of the hills reaching a general elevation of 1300 to 1400 feet above sea level. The deepest valleys are cut down to 1100 or 1200 feet, so that the local relief is only about 200 feet. The hills are so moderate in slope that practically all roads are laid out in the rectangular system of the township and section lines. The valleys branch in dendritic or tree- like fashion. There are no lakes and practically no swamps [near Marathon]. A view from a hilltop shows an even skyline in every direction.
In the peneplain of northern Wisconsin there are two distinctive kinds of topography, related directly to the underlying rocks. These are (a) the upland plains and (b) several types of ridges.
The smoothness of the upland plain is evidenced by the route for the old Fort Wilkins and Fort Howard wagon road. It was straight for 33 miles from Fort Howard, near Green Bay, to Shawano. Then it turned and ran across the Northern Highland through Crandon to State Line in Vilas County, a distance of 100 miles, straighter than the flight of Arctic water fowl.
Where the peneplain is cut by streams the hills are of inconsequent pattern. This is because the underlying rocks are homogeneous in their resistance to erosion. Topographic features are without marked trend, and branch irregularly with the branching of the streams.
In other parts, the hills are related to underlying rocks which are not homogenous over large areas, but along narrow belts. For example, in northwestern Wisconsin, the Keweenawn lava flows have been acted upon by weather and erosion so that they form parallel ridges, usually with a steep slope on one side and a gentle slope on the other. These low, flat monoclines are often made up of alternating weak and resistant layers, the resistant layers forming the crests and back slopes of the ridges, the weak layers forming the bases of the escarpments and the intervening lowlands, as in the douglas, St Croix and Minong copper ranges of Douglas, Bayfield, Washburn, Burnett, Polk and adjacent counties.
[Both the preceding types of ridges have] crests rising to about the same level and to about the level of the gently- sloping peneplain. Other ridge crests rise distinctly above the peneplain level. These are known as monadnocks. Monadnocks stand up above the level of the Northern Highland because the rocks are much more resistant than those in the surrounding areas. Examples are the Penokee Range, Flambeau Ridge and other quartzite hills of Barron and Chippewa counties, Silver or McCaslin Mountain, Thunder Mountain in Marinette County, and Powers Bluff in Wood County.
Rib Mountain whose highest point is 1940 feet above sea level, is one of the most prominent monadnocks in Wisconsin. It is a quartzite ridge, rising 640 miles above the general peneplain level, about 4.5 miles southwest of Wausau. Its top is about 800 feet above the Wisconsin River near Wausau. It is about three miles long and more than a mile wide. A short distance away are two other quartzite monadnocks Mosinee Hills and Hardwood Hill.
The Penokee- Gogebic Iron Range of Wisconsin and Michigan is about 80 miles long and half a mile to a mile wide. It is a long, narrow monadnock, similar to Rib Mountain, though of much greater magnitude. The crest of the range rises 100 to 300 feet above the broad valley to the north. In some places the range is broad and gently rounded, in others it is narrow, steep- sided and serrated. The highest point on the crest of the range is Mt Whittlesey, 1866 feet high and the third- highest point in Wisconsin.
A portion of the Penokee Range is broken by many gaps. In each of these gaps, except three, streams flow northward across the range. The streams are all of moderate size, often with waterfalls and rapids in the narrow gorges where they cross the resistant rocks of the Penokee Range. The gorges which cross the Penokee Range are preglacial and unusually numerous. In the 30 miles between the Montreal and Bad rivers there are nine water gaps.
These passes in the barrier formed by the Penokee Range are a great aid in transportation. Just as the Devils Lake Gap in the Baraboo Range determined the position of the Chicago & Northwestern Railway in that monadnock and for many miles to the south, so the Penokee Gap of Bad River controlled the route of the Soo Line for miles to the south. A large number of the iron mining towns are located opposite these gaps.
Glaciation of the Northern Highland
The portion of the Northern Highland in the area of Wisconsin glaciation forms a striking contract with the Driftless Area. There is no residual soil. Instead, there is a transported, glacial soil. Rapids and waterfalls are abundant in the streams. there are large undrained inter- stream areas. Lakes and swamps are found everywhere. The drainage pattern is most irregular, resembling nothing systematic, as is perfectly normal for so youthful a drainage system.
It is interesting to note that the second highest point in Wisconsin, so far as now known, is not a conspicuous rocky peak but a morainic hill. It is about 1891 feet high and is situated east of Ogema, Price County.
The form of the peneplain surface has been slightly modified by the glacial deposits. Three principal sorts of topographic forms are found, (a) the terminal or recessional moraines, (b) the ground moraine, and (c) the outwash deposits.
In various parts of the Northern Highland the thickness of the glacial material in terminal moraines varies from 75 to 100 feet. It has a probable maximum of 350 feet, in the Wisconsin Valley moraine north of Merrill, Lincoln County, and perhaps as much as 500 or 600 feet west of Ashland.
The material is, variably, unassorted till or stratified sand and gravel. The till, or boulder clay, is made up of find clay, sand and subangular, striated boulders of various sorts. It is un- assorted because deposited directly by the melting ice. The stratified sand and gravel is material carried by streams from the melting glacier and is, therefore, assorted. The surface form of the terminal and recessional moraines is sometimes a smooth, broad- topped ridge, sometimes a hilly mass of knobs and kettles, the latter often containing lakes and small swamps.
The ground moraine covers a wide area, in contrast with the terminal moraine which is found in narrow strips. Its thickness is from a few inches to 100 feet or more, and the material throughout much of the area is unassorted till. There is apt to be a rolling surface, sometimes with broad swells and shallow sags, the latter often containing enormous swamps.
Outwash deposits cover vast areas in the Northern Highland. the thickness of the sand and gravel deposited by streams from the melting ice often exceeds 30 or 40 feet. In one case in the Namakagon valley in Washburn County it is more than 160 feet. Some of these outwash deposits cross the Driftless Area.
Another type of glacial stream deposits are eskers, formed in tunnels beneath the ice. They are sinuous ridge of rounded gravel and may be found, among other places, in northern Florence County.
[As a result of the profound affects of glacial occupation,] vast areas of the Northern Highland are better suited to forest than to crops, especially as large areas are swampy. The lakes are a source of steady water supply for the rivers that flow from this highest part of the state, as well as an asset in the lumbering industry and an attraction to fishermen and summer visitors. The rapids and waterfalls furnish invaluable water power. The iron deposits . . . are more difficult to find than in a region of residual soil, being often deeply buried.
Lakes and Streams of the Northern Highland
The glaciated portion of the Northern Highland abounds in lakes and swamps in two groups one in northwestern Wisconsin at the headwaters of the St Croix and Chippewa Rivers, and the other in the extreme northern part of the state at the headwaters of the Flambeau branch of the Chippewa, and the Wisconsin, Wolf and Menominee rivers. F H King wrote in 1879:
"Nearly all of these lakes, so far as observed, possess the characteristics peculiar to those of broad, morainic belts. They are beautiful sheets of water, clear, soft and deep, encircled by bold, fantastic rims, and dotted with tree- clad island cones of such varied beauty in the autumn season, that as one looks in unexpectedly upon them up the rapids of the narrow shaded rivers, he forgets his fatigue and revels in an exquisite garden of foliage plants. Sometimes a fringe of white cedar lies upon the water's edge; higher up a wreath of white birch, then a belt of poplar, and, capping the rounded hilltops, maple and yellow birch, throughout all of which there is a generous setting of rich green white and Norway pines."
[In northwestern Wisconsin,] the numerous lakes of Washburn, Burnett and adjacent counties are in a region of Wisconsin drift. Among the larger and better- known of these bodies of water are Upper St Croix, Namakagon, Court Oreilles, Chetac and Chetek lakes. Some of them have no outlets. Most drain into the Chippewa and St Croix rivers. Marshes are also abundant. Peat swamps occupy two- third of some townships in western Burnett County. There are (a) open marshes with low timbered knolls, (b) heavily timbered swamps, and (c) wet swamps subject to overflow.
The narrowness of the portage from the St Croix to the Bois Brule River made this an important highway of communication between Lake Superior and the Mississippi. Thus it was so familiar to the Indians that the earliest white explorers learned of it at the very beginning and utilized it frequently. This was also true of the route from the Chippewa valley to Chequamegon Bay by way of the several headwaters of Bad River. Du Luth crossed the Bois Brule portage in 1680, Carver traveled that way in 1767, Le Sueur in 1693 and Schoolcraft in 1832.
The Highland Lake District of northern Wisconsin lies in Vilas, Oneida and adjacent counties. Their total number and closeness of position may be inferred from the fact that, although one of the largest of these bodies of water, Trout Lake, covers only 6.5 square miles, the 346 lakes and ponds of Vilas County occupy 140 square miles, or more than 15 percent of the area of a county nearly as large as the state of Rhode Island. In few parts of the world are there more lakes to the square mile.
These are, as a rule, small lakes, closely spaced, irregular in outline, and connected by streams which have the most irregular courses. All this is typical of lakes in a glaciated region, but the origins of the lake basins are diverse. Some are in shallow depressions in the ground moraine, some are held in by recessional moraines, and great numbers are in hollows in the outwash gravel plains.
Open swamps or marshes in northern Wisconsin often go by the Indian name "muskeg." There are also cranberry and blueberry swamps and drier marshes and swamps not called muskeg, as well as level tree- covered tamarack swamps and hummocky cedar swamps. Some of the marshes are filled lakes, but a larger number are merely regions of poor drainage due to glacial accumulations.
[The Upper Wisconsin River, the Menominee River, and the Wisconsin- Michigan Boundary in Relation to Rivers and Lakes are discussed in detail beginning on page 417 of the book.]
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