Last year, Forest Preserves of Cook County staff tested a new approach to protecting rare habitats at the top of the bluff at Swallow Cliff. The results have been so impressive that next month, the pilot program will be expanded to other nearby locations in the Palos Preserves.
The issue: an extensive system of unofficial trails that look inviting to too many hikers, bikers and even horseback riders. But wandering off designated Forest Preserves trails can trample plants, disrupt wildlife and even be a danger to your safety. Swallow Cliff Woods, which is one of Cook County’s most visited preserves and is known for its high biodiversity, has suffered extensively from this activity.
“It is a major problem,” said regional ecologist Kristin Pink, who was one of the leaders of the pilot project. “People may just think, ‘Oh, it’s just a trail. I wanna go and see this place.’ But they have real tangible, detrimental effects on wildlife, plants and the natural areas as a whole. Swallow Cliff is probably the worst site, but this is a problem throughout the Forest Preserves.”
Swallow Cliff has about 3.5 miles of official trails, but the preserve also has had about eight miles of unofficial trails. Not only do those extra miles mean less ground for native plants like wild geranium (Geranium maculatum), yellow violet (Viola pubescens) and Short’s aster (Symphyotrichum shortii) to grow, they also bring more human activity into the woods, limiting the space that animals feel safe. Swallow Cliff is about 740 acres, but with the unofficial trails and a “corridor of influence” buffer zone, wildlife has been confined to about 100 acres.
“We have incredibly rare ecosystems preserved right here in urban Cook County. Going off our official trail system is severely impacting the habitat there,” Pink says. “It’s very disheartening.”
To deter this kind of behavior, in summer 2023 the Forest Preserves installed a sign at the base of the Swallow Cliff stairs that explained the damage that can be done, and in the woods installed “Please STAY OFF unofficial trails” signs at key spots and placed barriers at those trailheads.
From July 2023 to July 2024, the Forest Preserves collected data, capturing more than 9,200 photos from trail cameras and taking measurements of the width of trails and noting returning vegetation at the sites.
They found that the deterrents worked, reducing the trails’ use by 80 percent. With less foot traffic on these trails, some plants completely covered up trailheads with others making progress.
Pink and her colleagues were thrilled by the results but not surprised.
“I do think that when you tell people why and you ask them to do the right thing, most people want to do the right thing,” she said. “Most people want to do right by nature. I think a large part of it is giving people a reason why—helping them understand why we’re trying to do this, not that we’re just trying to limit their use of this site.”Seeing the success of this pilot study has the Forest Preserves adding more locations that can benefit. More signs and are going up this spring at McClaughrey Spring Woods and Teason’s Woods to hopefully spread the restoration work.
For these locations, it is not just about the safety of plants and animals, but to the trail users as well. Swallow Cliff is home to prairies, savanna, woodland forest and wetland—and also a rare geologic deposit known as Lemont Drift, which is comprised of very fine sand topped with a thin layer of clay. When the clay is disturbed, the sand erodes and creates a dangerous situation for anyone nearby. Some of the unofficial trails run over Lemont Drift.
“It’s potentially a safety concern for people, but then it’s also bad for nature,” said Pink, noting that the site’s name is from the bank swallows that make a home in the spots with exposed sand. “We want to allow people to enjoy this site but also provide a home and habitat for plants and animals.”