Highlights
20-acre demonstration wetland restoration attracts 110 bird species and is helping to keep the Chicago River clean

Stats
The entire preserve is 431 acres. Prairie Wolf Slough native habitat comprises 40 acres; 2 miles of trails

Behind the scenes
The prairie has been routinely burned since 1994. The slough doesn't burn entirely, but even partial burns keep it open for birds

Getting there
Take Route 41 (Skokie Highway) to Route 22 (Half Day Road). Go west about one mile. The parking lot is on the south side of the street. There is construction on Route 22, but the preserve remains open

Winter 2005

Small woodlands, prairie, and wetland restorations adjoining a large dog-walking area

Lake County, Illinois

"I joke that we should put a room number on Prairie Wolf Slough because so many students are there so much of the time," says Al Pilgrim, co-steward of the 431-acre Prairie Wolf Forest Preserve near Lake Forest, Illinois. Students from Deerfield High School, linked by a trail from the south, do come here a lot — to study the nearby ecosystems for classes, to take field exams, and to help restore the site. Even the cross-country running team trains here. The school is just part of a nine-year community effort to return a functioning native wetland system to this preserve.

From Route 22, Prairie Wolf Slough is an unassuming flat expanse surrounded by office buildings and bounded on the east by the Middle Fork of the Chicago River. While a majority of the site north of Route 22 is unmanaged meadow and a 44-acre permit-only dog park, the 40 acres of wetland, prairie, and savanna being restored in the south (known as Prairie Wolf Slough) are worthy of a trip out on a lunch hour to watch the seasonal changes in the rebounding native ecosystem.

Woodchuck. Photo by Peter Dring.

When the district purchased Prairie Wolf in the late 1970s, the site was largely agricultural, but 200-year-old red oaks reigned steadfast in the 13-acre mesic woods and oak savanna. Ninety-eight native species survived there, including large flowered trillium, sensitive fern, tall white lettuce, and turtlehead.

In the winter, hikers and skiers can look for muskrat tracks in the snow or on the mudflats, as well as mink, weasel, fox, and coyote tracks. Muskrats feed on the aggressive stands of cattails here and harvest the leaves to make distinctive cone-shaped houses.

In the mid-1990s, under the direction of Friends of the Chicago River, 14 groups collaborated on a significant project here to demonstrate the importance of healthy wetlands in filtering out contaminants, holding water during storms, and providing habitat. Water flowing off of countless paved surfaces in the surrounding watershed drained straight over the preserve's agricultural fields into the river, carrying pollutants, fertilizers, and pesticides. In 1995, the district removed drain tiles and graded the fields to create a natural slope from the savanna to the river. Nearly 40 booted volunteers fanned out to scatter millions of wetland and prairie seeds around the newly formed slough and surrounding land. DePaul University researchers installed monitoring boxes to analyze water coming in and out, and a floodgate controls water levels to sustain wetland species and reduce flooding downstream.

Later, volunteers planted almost 61,000 native plugs in the slough. The site now attracts more than 110 bird species: birders report great egrets, nesting indigo buntings - even a semipalmated plover in breeding plumage. The low, wet areas provide refuge for chorus frogs, toads, painted turtles, and an occasional soft-shelled turtle from the river.

"The site was one big mud hole," recalls Pilgrim. But now, he says, "it's been transformed into a living thing." To volunteer for workdays, call (847) 968-3329.

— Alison Carney Brown

See also: History of Prairie Wolf Slough