Revitalizing Native Ecosystems

Looking around the wide-open prairies, woodlands, wetlands, and oak savannas at Deer Grove, it’s hard to imagine that it was ever overgrown with invasive species that prevented native plants and animals from thriving in the area. If you visited the site a decade ago, you would barely be able to see through the shrubs that surround the preserve, creating a dark and dismal wooded trail. Many of the wetlands in the preserve were dried up and the now-expansive prairies were once used for decades as farmland. Before restoration, the woodlands were a jumble of different species, planted without much thought to their ecological impact. The woods were being suffocated by buckthorn and other invasive species, causing the younger, native trees to die due to a lack of sunlight.

To offset the effects of an expansion at O’Hare, Openlands received funding from the O’Hare Modernization Mitigation Account (OMMA) in 2008 to restore wetlands at five different sites in the Des Plaines River Valley. In 2008, Openlands partnered with the Forest Preserves of Cook County, City of Chicago Department of Aviation, and the U.S. Army Corps of Engineers to begin the savanna, prairie and wetland restoration efforts on the eastern half of Deer Grove. In 2015, we announced that Deer Grove West would also receive significant restoration – just in time for the Forest Preserves of Cook County’s 100th Anniversary. We are currently implementing a restoration plan to heal natural processes to this preserve to support more than 300 species of native woodland plants, as well as a wide variety of birds, reptiles, amphibians, and mammals.

With our partners and many volunteers, we’ve successfully restored the rare, native ecosystems found in Deer Grove East, creating a beautiful and conservation-friendly preserve for visitors to enjoy.


To restore the rare ecosystems found at Deer Grove East, Openlands relied on both a team of dedicated volunteers and professional contractors.

Until the Forest Preserves of Cook County purchased Deer Grove East in 1939, the prairies and wetlands were being used as farmland. This meant that farmers placed drain tiles underground to prevent the land from getting too wet, which allows for planting to begin earlier in the year. However, these drain tiles also lead to natural wetlands drying up and no longer being able to flourish. Even after the Forest Preserves of Cook County acquired Deer Grove East, the drain tiles were not removed, which meant that even though the land was no longer being used for agriculture, it still was unable to return its natural state. Openlands worked with professionals to locate the drain tiles and remove them from the area to allow water to flow naturally and return to the land.  

In the woodland areas, the first major step was determining which trees should stay and which should be cleared, as well as getting rid of the invasive buckthorn that was choking the woods. Many of the trees had been planted in the area without much thought about whether they belonged there and made it harder for the natural oak savanna ecosystem to thrive. With the help of prescribed burns, the clearing of invasive species, and the planting of native species, Openlands was able to restore the oak savanna­ – open canopy oak woodland with lots of low- and mid-growth prairie plants between the trees. While the main portion of restoration is complete, volunteers still help Openlands and the Forest Preserves maintain the land. The Weed Scouts, a part of the Deer Grove Natural Areas Volunteers, patrol the trails looking for and removing weeds or other invasive species that have sprouted up among the native plants.


Following restoration, Deer Grove East is now home to 389 different native plant and animal species and is a great place to spot birds like sandhill cranes, Henslow sparrows, red-headed woodpeckers, and bobolinks. Other animals, like blue-spotted salamanders, chorus frogs, and spring peepers also make their home around the preserve.

While Deer Grove East is an important space for wildlife, it also is representative of three of Illinois’ scarcest habitats: prairie, wetlands, and oak savannas. Since Europeans first settled in the area, native habitats around the state have been severely depleted. Over the past 200 years, Illinois has lost 90 percent of its wetland habitats, 99.9 percent of its high-quality prairie, and the vast majority of its midwestern oak savanna. These habitats are essential to protect because they provide beautiful recreation areas for the community, and provide a safe home to native plants and animals.

Not only is Deer Grove East a beautiful place to spend time, but it also acts as an industry model for successful restoration.