Spring 2000

Boulders and rocks left by glaciers in the ice age saved this prairie from the plow. There are currently no trails, but high-grade prairie awaits those willing to navigate a fence

Will County, Illinois

Grant Creek Prairie is really a gift of the Ice Age. Thousands of years ago glaciers scoured much of Illinois, clear down to the southern part of the state. Thousands of feet thick, they leveled hills and rocky outcrops and brought huge boulders and debris with them from as far away as Canada.

Grant Creek Prairie Nature Preserve is a 78-acre site of very high quality dolomite to wet/mesic prairie whose roots are in 2-3 feet of black topsoil and glacial loess. Glaciers scraped down to the dolomite bedrock of the Niagaran formation leaving only a couple of feet of soil. Over time, organic remains contributed to the richness of the black earth.

The glaciers also left their calling cards in the form of glacial erratics — boulders and large rocks — which kept this area from being cleared and plowed under, although it was probably grazed at one time.

Dedicated as a state nature preserve in 1978, a sign of its high quality as a site, Grant Creek has more than 100 native plant species, including spiderwort, rattlesnake master, leadplant, compass plant, prairie dock, and prairie rose. Visitors might see red-winged blackbirds vigorously defend clumps of tussock sedge and great blue herons and egrets flying overhead on their way to the Kankakee River, just one mile to the south. Across the Kankakee, one might find 275 million year old fossil relatives of the horsetail rushes so plentiful on this site.

Due to its wet nature, reptiles and amphibians, like the fox snake, green snake, chorus frog, and American toads, call Grant Creek Prairie home. Mammals include coyote, wolves, whitetail deer, shrews, and mice.

There is an ongoing program of clearing hawthorn trees and this project is nearly complete. When this area was originally acquired, the hawthorns had shaded out a number of areas and were dominating the area.

Visitors are warned to drive slowly on the frontage road as it is very rough.

For further information contact site superintendent, Des Plaines fish and wild life area, 24621 N. River Road, Willmington, IL 60481, or site steward Bill Glass at (815) 423-6370. At present there are no facilities, trails, or recreational opportunities and the entire site is fenced. (However, there is an opening that the agile can climb through.) For those who appreciate seeing high-grade original prairie, it is well worth a trip.

— Jim Kostorhys