Forest Preserve District of Cook County, Illinois
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The Palos Preserves: Part One -- Their History
Nature Bulletin No. 710   March 23, 1963
Forest Preserve District of Cook County
Seymour Simon, President
Roberts Mann, Conservation Editor


The Palos forest preserves now comprise approximately 13,750 acres of the most hilly, wooded and scenic parts of Cook county, and include almost 100 lakes, ponds and sloughs. They occupy 10,051 acres in Palos township. The remaining 3700 acres are situated in the adjoining townships of Orland, Lemont and Lyons.

In 1850, when Cook county was organized into 27 townships -- now there are 38 -- one of them was called Trenton. After the first election its township board changed the name to Palos.

Reputedly, that was suggested by Melanchon A. Powell, one of the earliest settlers and first postmaster of Palos (originally "Orange") because of a tradition that one of his ancestors had been a member of the crew on one of the ships commanded by Christopher Columbus when they sailed from Palos de Frontera in 1492. Palo, in Spanish, may mean a tall tree, the mast of a ship, or a promontory. Palos de Frontera was a seaport beneath a promontory on the Gulf of Cadiz, about 45 miles from Seville.

The first purchase of land by the infant Forest Preserve District of Cook County was authorized on September 25, 1916. It comprised 42 parcels totaling 288.50 acres -- wood lots varying in area from one to 17.68 acres -- at an agreed price of $90 per acre. They were in what was designated then as Preserve No. 1, now Deer Grove.

The second purchase authorized on that same date, was in the Palos, then designated as Preserve No. 4. Joseph S. Halligan and his heirs or assigns were paid $10,605.48 for 80 acres: the south 1/2 of the S.E. 1/4 of Section 9 in Palos Township. By 1918, 2370 acres in that township had been acquired.

The distinctive character of the Palos preserves stems from the geological history of that region. The last glacier of the Ice Age created the highlands -- vast deposits of clay, sand, gravel and boulders -- known as the Valparaiso moraine. As the glacier melted away it also created Lake Chicago which, 60 feet higher than the present Lake Michigan, discharged torrents of water through two outlets carved across that moraine: the DesPlaines river valley and the Sag valley. The triangular highland between them is known to geologists as Mt. Forest Island.

The extraordinary number of sloughs, ponds and potholes in the Palos region is due largely to the fact that as the glacier retreated, chunks of ice were left behind and surrounded with glacial drift. When a chunk melted, there remained a pocket, filled with water, in the moraine. See Bulletin No. 617: The Life History of a Pond.

The Palos preserves are divided into two principal sections by the Sag valley. Originally that was occupied by the vast Saganashkee Swamp which extended from the DesPlaines valley to Blue Island. From a low continental divide at about 86th Ave., it drained sluggishly westward to the DesPlaines and eastward to the Little Calumet river.

After the Illinois and Michigan Canal was completed in 1848, the Calumet Feeder ditch was dug through the swamp to furnish water for that canal. It was replaced by the narrow Calumet Sag Canal, started in 1911 and completed in 1922. Now the Cal-Sag is being widened, deepened, and will become a vital connection between Lake Michigan, the huge Calumet Industrial District, and the Chicago Sanitary and Ship Canal -- part of the great Illinois Waterway to the Mississippi.

Next week, in Part Two, we will discuss other unique features of the Palos preserves.

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