Palos Hills Geography

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The original landscape of Palos Hills is not visible. That physical setting of Palos Hills, as well as most of the rest of Illinois, was altered and covered by four glacial periods and more recently by the hand of man. Continental glaciers moved southward from Canada. Acting like massive bulldozers the glaciers leveled hills and filled in valleys. When a glacier would stop its advance, the material piled in front of its advancing edge would remain. Those hills of material are called moraines. As the glaciers moved down the basin of Lake Michigan, they left several moraines curving through the Palos area. Geologists gave those moraines names, names of towns that the moraines passed through.

Two moraines form the hill region located in western Palos Hills and the nearby communities. Those moraines are the Tinley Park and the Valporaiso Moraine. As one drives west on 107th street, it is very easy to recognize a rapid change in elevation of approximately forty to sixty feet. You have reached the edge of the moraines. At one time those moraines held back all of the water from the melting glaciers. That extensive area of water was called glacial Lake Chicago. It is right here in the Palos area where the moraines broke and the waters from glacial Lake Chicago poured through, the water flowing southwest (the initial rush of water has been given the term "Kankakee Torrent") creating a glacial spillway, a valley (hence the name moraine valley appearing so often in our area) and slowly lowering the level of Lake Chicago, until along with other events, Lake Chicago became Lake Michigan in its current boundary. (The Illinois State Museum has a web site explaining glaciers in this area. http://www.museum.state.il.us/exhibits/larson/content.html) (There are also many web sites with good general information about glaciers. All about glaciers from the National Snow and Data Center)


View 107th and Kean, top of Tinley Moraine looking east, moraine ends and elevation declines	View 107th and 88th Ave looking west, top of rise is 107th and Kean, the Tinley Moraine.	View 107th and 88th Ave looking west, top of rise is 107th and Kean, the Tinley Moraine.

View from top of Tinley Moraine at 107th and Kean looking south to 111th and the Sag Valley.	View from top of Tinley Moraine at 107th and Kean looking south to 111th and the Sag Valley.	View from top of Tinley Moraine at 107th and Kean looking south to 111th and the Sag Valley.

Other physical regions of our area derive their names from this geologic period. The higher areas, those that appeared first above the lowering levels of the lake waters, were called islands. Blue Island, Stony Island, and the largest of them right here in the Palos Area, Mount Forest island are the areas of higher elevation.

The moraine region contains many lakes, also remains of the glacial ages. These lakes are commonly called sloughs. Much of the moraine region and many of the lakes in the Palos area have remained public lands becoming part of the Cook County Forest Preserve.

Man has made significant alterations to the physical landscape of the Palos area. The lower portion of the glacial valley (south of Mount Forest Island), the sag, was dug deeper and became the Calumet-Sag Channel, drawing Lake Michigan water to flow toward and eventually reach the Illinois River, part of the plan to reverse the flow of the Chicago River. The northern portion of the glacial valley (north of Mount Forest Island) was dug deeper and became the Chicago Sanitary and Ship Canal, drawing Lake Michigan water to flow toward and eventually reach the Illinois River, another part of the plan to reverse the flow of the Chicago River. (The Metropolitan Water Reclamation District of Greater Chicago has a web site explaining this http://www.mwrdgc.dst.il.us/.) (The Chicago Public Library Web Site has a web page explaining the reversal of the Chicago River http://www.chipublib.org/004Chicago/timeline/riverflow.html)


Calumet Sag Channel at LaGrange Road	Illinois and Michigan Canal	Illinois and Michigan Canal near Lemont, Illinois

Chicago Sanitary and Ship Canal in Lemont, Illinois	Joining of the Calumet Sag Channel and the Illinois and Michigan Canal at the tip of Mt. Forest Island.

The land along 111th street in Palos Hills in its natural state was subject to flooding. That land was made less prone to flooding by early residents with the digging of a drainage ditch (the Lucas Ditch) and work on Stony Creek to channel waters to the Calumet-Sag Channel. When Moraine Valley Community College was constructed, retention ponds were constructed to hold the runoff. Later new sewage and runoff lines were constructed in Palos Hills. The Deep Tunnel Project also runs close to Palos Hills. (The Metropolitan Water Reclamation District of Greater Chicago has a web site explaining the Deep Tunnel Project)


Retention pond at MVCC view from 111th St.	Retention pond at MVCC view from 111th St.	Lucas Ditch as viewed toward the north as it crosses 111th.

Former claypit, near intersection of 111th and Southwest Highway.	Stony Creek as viewed toward the north as it crosses 111th.	Stony Creek as viewed toward the south, emptying into the Cal Sag.

The physical landscape at the intersection of 111th and LaGrange Road is also an alteration of man. That intersection was an area used as a clay pit. During the 1960's, it was a refuge dump, eventually sealed and covered. Today to the casual observer, it is a nice hill, seemingly part of the moraine itself. Another clay pit near the intersection of 111th and Southwest Highway, partially filled with water, has been considered for a number of uses, but today still remains unused and unimproved.

Older topographic maps of the Palos area indicate a seemingly chain of small ponds just north of 111th street intersecting Roberts Road. Those ponds are sloughs, they have been slowly filled in and are also nearly gone. They valley they were part of, running west of Roberts Road was also filled in. Today a subdivision of homes sits atop that landfill. The slope of land along 107th and 88th Avenue was redesigned in order to build homes in that area.


Slough just east of Roberts Road and 108th St. Picture taken in 1972.	Same slough. Picture taken in 2000.	Portion of filled slough now has a subdivision along its edge.

Land filled just west of Roberts Road and 109th street. Picture taken in 1972.	Land filled just west of Roberts Road and 109th street. Picture taken in 1972.	Small slough lake in the fen along 111th near LaGrange Road.

Fen between 111th and the Calumet Sag Channel, Kean to LaGrange Road.	Fen between 111th and the Calumet Sag Channel, Kean to LaGrange Road.	Fen between 111th and the Calumet Sag Channel, Kean to LaGrange Road.


Geology map showing moraines and lake plain	Relief map illustrating features of the Palos area.