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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

© Wisconsin Geological and Natural History Surveys
The "Landscapes of Wisconsin" map. Click on the map for a larger version.

© Wisconsin Geological and Natural History Surveys

December 2002

Get the big picture

Two maps help you see and feel the character of Wisconsin's geographic features.

Bob Gurda, Mindy James and David L. Sperling

How do we sense the lay of the land?

We make mental maps of our daily travels: the streets, routes and turns we need to negotiate by car or on foot. We note the bends of the river, the rock bars, stump fields and shoreline on the water. We hike the ridges to get a view from the top.

On longer trips we note the gradual transitions from farm fields to woods. Trips through eastern Wisconsin skirt the edges of eskers, kettle lakes and limestone outcroppings. To the southwest, we snake across ridge tops and wiggle through river valleys. Heading north, we cross the great marshlands and central sands before reaching deep woods country. To the northwest, we see forests, birch groves and dense groves of conifers.

We know the landscape is full of patterns but we are often too close to see them. The landscape changes in ways too subtle to be obvious when viewed up close. Sometimes, we just need to step back – way back – to get a sense of what we can't see for ourselves.

Two relatively new maps do just that. One, Landscapes of Wisconsin, profiles the highs and the lows of the Wisconsin terrain. It depicts changes in elevation and the geological features of the land surface. A companion map, Wisconsin Land Cover, depicts what covers that terrain – the forests, wetlands, farmlands and cities. It's as if the first map describes the size and shape of the face and the second, the detailed facial features that flesh out Wisconsin's physical character. The maps are interesting to study and hang on the wall as references. Both maps provide landscape details at a 1:500,000 scale, where one inch represents approximately eight miles on the ground.

We recommend starting with the Landscapes of Wisconsin map to get a sense of the shape, forms and relief of Wisconsin's landforms. Through the use of color and shaded relief, the map has a three-dimensional textural feel simulating the appearance of sunlight and shadow on a clear day. Wisconsin Geological and Natural History Survey staff developed the map by analyzing digital elevations derived from U.S. Geological Survey topographic maps that note roads, lakes and other land features.

You can clearly see the big differences on this 42 x 42-inch picture of the state. The depictions make it easy to see the lands to the southwest that were spared the crushing weight and abrasive power of glaciers that moved through Wisconsin from the northeast some 9,500 to 20,000 years ago. That tremendous force scoured and flattened lands, changed the course of rivers, built and deposited huge hills, and left plenty of evidence in its melting wake. The hills, valleys and drainage patterns all pop up from the map surface to show each ridge and rocky run. You can see the lower Wisconsin River Valley skirting Highway 151 and see the twin Blue Mounds. You can see the Military Ridge, which the present Highway 151 parallels east of Dodgeville, thereafter forming a thin brown line through Iowa and Grant counties. You can see it is no accident that I-94 runs through the flat country just east of the unglaciated hills at least as far as Black River Falls. The Baraboo Hills of Sauk and Columbia counties rise 700 feet like a rough dinosaur's back with a swishing tail.

As your eye scans northward, you can pick out where the edge of the icy glacial shield dropped off near Neillsville and the meltwaters formed the Black River, wiggling its way between the hills to settle in bottomland plains just west of La Crosse. It's even more noticeable where the Chippewa River south of Durand forms a delta that washes out into lowlands on the Mississippi River along the Buffalo and Pepin county lines.

A trapezoidal region 600 feet high rises in the Blue Hills of northwestern Rusk, southwestern Sawyer and northeastern Barron counties. Here the tough quartzite rock refused to wear away and beds of softer red catlinite rock were quarried and carved into pipestone. Two parallel ridges run roughly from Hurley in Iron County southwest into Ashland County. Accompanying text explains how the southern ridge, the Gogebic Range, was mined for iron for 80 years and the northern ridge, the Trap Range, is composed of a basaltic-lava rock that arcs under America for 1,200 miles to the southwest and northeast.

Landscapes of Wisconsin does a good job of letting the visuals tell Wisconsin's story while offering small blocks of commentary to describe the Northern Highlands, the Central Sand Plain that is now the heart of our potato, cranberry and vegetable growing region, the drumlins and kettles of southeastern Wisconsin and the Green Bay/Fox River lowlands. It lays a good foundation for mentally overlaying the map of current land cover.

The two maps in tandem make a truly dynamic duo for understanding the present landscape and its potential. The terrain and the current vegetative cover are tightly linked. Elevation, drainage and soil type affect the vegetation. In other cases, geologic formations like the rocky ends of moraines are so choked with stones and boulders or the slopes are so steep that the soil is impractical to till. Those areas could grow trees instead of crops.

Wisconsin Land Cover uses computer and satellite technology to take a long view of the land. The details came from Landsat satellites in orbit 438 miles above Wisconsin in the summer of 1992. The satellite took pictures using electronic technology that sensed ranges of both color and near-infrared energy reflected by leaves, pine needles, sand, rock, water, crops and urban areas. The data was collected in a grid that precisely located each 100 x 100-foot cell as pictures were taken statewide. The satellite computer data stored 160 million cells of information about Wisconsin. DNR field staff then made field observations using GIS equipment and aerial photographs to categorize the land cover in 15,000 places. Finally, computer analysis of the satellite images assigned a land cover category to each cell. Information from the 15,000 ground observations was compared to gauge the accuracy of the categories assigned by the computers.

DNR geographic information specialists interpreted the satellite data from start to finish. That data is now available for land use planners, environmental scientists and other cartographers. Then, working with the State Cartographer's Office and the Wisconsin Geological and Natural History Survey, the database was plotted and combined with text and other elements to create the 42 x 50-inch printed Wisconsin Land Cover map.

You can see in an instant that the Wisconsin Land Cover map tells a very different story. It's more colorful in representing current land uses. The Landscapes map was presented in natural shades of green and brown to help non-geologists by simulating an aerial look at the underlying rocky landscape. The Land Cover map appeals to our flashier sense with brighter colors to distinguish areas. The "hot zones" in cities where people are more packed together are shown in red grading to a lighter pink as we spread out a bit in the 'burbs. Cropped agricultural land is shown in pleasing yellow, grasslands in an olivey brown, and shrublands in a darker brown hue. Forests of three types are depicted in shades of green, open water in light blue and forested/unforested wetlands in contrasting shades of purple and lavender.

Because each tiny cell is only 1/400th of an inch at map scale, each dot and spot of color merges on the page and in the mind's eye like a Seurat painting to form an impression of the landscape. Some of the patterns are easier to see. We note where cities give way to grasslands and farming. We can clearly sense that most regions are not purely devoted to one activity or cover type but are mixtures of forests, grasses and ag lands. You can see the vast low wet areas of former glacial Lake Wisconsin radiating from Wood, Juneau and Jackson counties. Rich and widespread wetland areas dapple the map, and it's easy to trace the terminal edge of the glacial reach we are now trying to mark in the Ice Age Trail. Again the great river systems and deltas are easy to spot.

Other patterns take more of a trained eye to see, and the narrative gladly leads the way. Yellow farmlands of western Wisconsin yield to shrubby forests and grasslands in the hilly lands and coulees. Take a close look south of the red cluster around Baraboo and you can pick out the grasslands of the former Badger Army Ammunition Plant complex as well as the wooded Baraboo Hills. South of Stevens Point and Wisconsin Rapids you'll note the bright greens of pine forest plantations and yellow irrigated croplands. Menominee County appears as a cool sea of green stippled with blue marking extensive forests, waters and wetlands. A triangle of yellow northwest of that green oasis marks where the silt loam blanketed over the glacial till around Antigo and formed rich farm soils.

The map's vast green areas do a good job of defining the edges of the great Northwoods. But the story of Wisconsin's glacial runs are better told in depictions of wetlands than on traditional road maps that show only lakes. Striated blue wetlands sweep across Taylor, Rush and Price counties, clearly showing the path and direction of healed glacial "scars" that gouged through the land, leaving wet remnants in farmlands and forests. Similarly, wetlands parallel to the drumlins and hills south of Lake Winnebago in Fond du Lac, Winnebago, Green Lake and Dodge counties look like blue spattered paint thrown from the north and east.

For a closer look than we can supply here, you can order these maps by mail or phone and can print order forms from the web. Landscapes of Wisconsin is available for $10 plus shipping, handling and sales tax from the Wisconsin Geological and Natural History Survey, 3817 Mineral Point Road, Madison, WI 53705-5100; or by telephone, (608) 263-7389. For order blanks, visit Wisconsin Geological and Natural History Survey.

The Wisconsin Land Cover map is available for $10 from the State Cartographer's Office , UW-Madison, Science Hall, 550 N. Park St., Madison, WI 53706; by phone, (608) 262-3065. See State Cartographer's Office to print an order form.

Bob Gurda is the assistant state cartographer at the State Cartographer's Office; Mindy James is publications manager for the Wisconsin Geological and Natural History Survey; David L. Sperling edits Wisconsin Natural Resources. All work in Madison.