The vast central area of the U.S., into Canada, is a landscape of low, flat to rolling terrain in the Interior Plains that gradually rises westward up to 5000+ feet in the unit known as the Great Plains. Most of these plains are now converted land use-wise to farming. A typical Great Plains view of such country is shown by a Landsat image of Kansas. But, in various areas, especially in western North and South Dakota and eastern Montana, erosion has produce gullies and small canyons. A scene including part of the Black Hills is illustrative of this.

### Chicago, Illinois and the Midwest

Proceeding westward, the plateau topography gradually gives way to gentle rolling hills and then (in central Ohio) to flat lands converted principally to farms and urban areas. This first image is just west of the transition between Appalachian-controlled topography and the Interior Lowlands. The scene is that of Cleveland (blackish area on the shore), Lake Erie with partially melted ice in March of 1973, the widespread farmlands of northern Ohio and southern Ontario, and low hills and lakes (mostly from the last glacial retreat) near Akron.

Cleveland's downtown and waterfront look like this:

The land remains hilly between western Pennsylvania and just east of Columbia, Ohio. Thereafter, the land becomes much flatter. Here is Indianapolis, Indiana , the home of the Indy 500, as seen by Landsat in late Fall:

Typical of the Interior Lowlands is the region around Chicago, Illinois, shown in this Landsat MSS scene.

The underlying rock type in the Illinois part of the Interior Province is limestone, but nearly all of the surface here is controlled by glacial deposits. The rich soils from these materials promote farming, of which corn, soybeans, and oats make up the major crops. Most of fields in this scene are rectangular, and many now are fallow (tan-colored) after harvesting. Trees cluster along the banks of rivers such as the Illinois, Des Plaines, and Kankakee that stand out among the farms.

The Chicago Loop (named for the rectangular track layout of elevated trains) reaches to Lake Michigan in the dense central downtown which is visible as blue tones, while much of the surrounding metropolitan areas are expressed by the reds denoting trees in suburban settings. Look in the image for features near the waterfront and compare with those in these two aerial oblique photos of that area:

Chicago sits along the southwest tip of Lake Michigan, one of the five Great Lakes. All of them originated as basins cut by glacial scouring and, in places, from damming by moraines. Gary, Indiana is the blue area at the southern tip of the Lake.

6-8: What time of the year was this image probably made? Near Gary, IN, note the wispy clouds extending north-northeast into the Lake; what might they be? ANSWER

Another major Great Lakes city lies almost due east of Chicago. Detroit, Michigan is built along the Detroit River which connects Lake Ontario at its northwest end with Lake St. Clair above a peninsula in Canada on which Windsor is situated across river from Detroit. Both cities are shown in this aerial view:

These two Landsat subscenes shows part of this metropolitan complex; the second, Landsat-7 ETM+, presents a higher resolution version in natural color.

Cleveland, Ohio lies astride the southeasstern shores of Lake Erie. Here is the central city imaged at 4 meters by IKONOS on April 26, 2000:

Another area within the glaciated part of the Interior Lowlands is southern Minnesota. In the next scene, farmland with many glacial lakes is predominant. But, Minneapolis and St. Paul just to its east appear (blue patches near top center) along a part of the upper reaches of the Mississippi River (whose headwaters begin to the northwest) that make that mighty stream much narrower in this part of its course. The Minnesota River joins the Mississippi from the southwest; the St. Croix River to the east forms the border there with Wisconsin which then continues southward along the Mississippi.

South of the glacial boundaries, the Interior Lowlands is a mix of farmlands and forests, in flat to rolling hill country. This next scene in Tennessee is typical. Nashville, Country Music's capital, lies on the Cumberland River. To the southeast (lower right) is the edge of the Cumberland Plateau (assigned to the Appalachian province and equivalent to the Allegheny Plateau); its prominent west-facing scarp continues both southward and into Ohio east of Columbus. Nashville is near the edge of the Nashville Dome, a gentle upwarp of sedimentary rocks (mostly limestones); its broad outline is elliptical, and is indicated by forests (evident in the image) that selectively concentrate on soils from certain sedimentary units.

Primary Author: Nicholas M. Short, Sr. email: nmshort@ptd.net