The sun had sunk behind the trees. In the fading light, the woods were dusky shadows.
And faintly, just barely, I thought I heard something.
I stood still and listened in the quiet of the darkening forest.
Hoo hoo hoo. Hoo.
An owl. I was smiling as I walked on, then stopped. About 30 feet ahead, two deer were standing next to the trail, staring at me. Then one jumped back into the brush, and they were both gone.
Night was falling at Waterfall Glen Forest Preserve in Darien, and I was taking a different kind of walk.
Nature at night is quiet, mysterious. It is a place of dark woods and of strange rustlings, of owl hoots and coyote howls.
"The people have gone home; it's the animals' time," said Ray Soszynski, senior ranger with the Forest Preserve District of DuPage County, who leads night walks at Waterfall Glen. "The nocturnal animals are waking up and starting their day."
Ranger-led programs are the only way to experience night well after dark in area forest preserves; most close at sunset, including those in Cook, Lake and McHenry counties.
But the DuPage County preserves stay open for an hour after sunset. You can stay on the trails as the sky darkens.
Not everyone would want to; some before-sunset walkers I spoke to said they thought the trail would be frightening after dark.
But Gina Early does so several times a week, walking her dog, Champ.
"It's peaceful; it's quiet; and the animals come out," she said.
She and Champ had stopped to watch the deer too. Early, who lives nearby in unincorporated Hinsdale, has seen coyotes and foxes. She has heard owls hoot and seen great blue herons walk across the trail.
And between Champ's company and her familiarity with the trail, she feels safe.
The preserves are safe, said Tom Wakolbinger, chief of police of the Forest Preserve District of DuPage County. As for evening visits, "if we didn't think it was safe, our preserves wouldn't be open after sunset," he said.
"People should use some common sense," he said. "I wouldn't recommend that somebody go out there at dusk and later by themselves if they're not in an area they're very comfortable with. Every once in a while, we'll have someone get lost at Waterfall Glen. Once that sun goes down, all of a sudden it's really dark."
But "it's a beautiful time to be out," he said, sounding more like a naturalist than a police chief. "It's quieter; there are fewer people around; and right now it's a beautiful time of year."
I found myself wishing I had brought a friend on my walk. Between the dark and the absence of other people, it was a little unnerving for a solo stroll.
On the other hand, the solitude was part of the magic. In the quiet, I heard every rustling and tried to figure out what animal had caused it. And a lone walk that featured tall pines silhouetted against the sky and a single star glowing in the west had a powerful appeal.
As for the rustlings I was hearing, they are signs that a lot is happening at sundown. "Great horned owls are becoming more active ... at dusk," Soszynski said. "White-tailed deer are moving, feeding. You have raccoons, skunks, opossums, even the coyotes are getting a little bit more active at dusk."
Owls and coyotes are calling, said Jim Carpenter, director of the Forest Preserve District of Cook County's Sand Ridge Nature Center in South Holland , which is offering a Night Owls walk Friday night: "Particularly early at night when the family members start to gather, you hear howls, yips and barks. You can even distinguish the individuals by the different sounds."
He tells people on night walks to walk quietly, and listen. "The main thrust of our night hikes is to get people to utilize senses other than our vision, which is the most dominant of our senses," he said. "People experience things at a time and in a way they normally don't get a chance to do."
"There are just strange sounds at night," like the loud warning snort of a deer, said Carl Strang, a naturalist with the Forest Preserve District of DuPage County who leads night hikes at Mayslake Peabody Estate in Oak Brook.
Katydids and crickets are singing at night, he said; great horned owls are hooting as males and females call to one another and to establish their territory; some migrating birds are calling as they fly overhead at night.
And sometimes coyotes howl or bark at a train whistle or ambulance siren.
"They think it's another (coyote) family," Soszynski said. "They don't mean any harm; they're just letting you know, 'Hey, we're here, too; you're getting into our territory.'"
Even in low light, there are sights to see — bats emerging for the night or, depending on the phase of the moon, and luck, an owl.
Our eyes adjust to darkness. "I tell people during my astronomy programs ... that a fully dark-adapted human eye can be up to a million times more sensitive than in broad daylight," Carpenter said.
At Waterfall Glen toward the end of the hour after sunset, the trees looked like a wall of darkness. I spent the last 10 minutes sitting at a picnic table listening to frogs calling across the parking lot.
I could hear Interstate 55, too, but somehow, watching the stars come out, it felt far away.
IF YOU GO
DuPage County forest preserves stay open for one hour after sunset. Between ambient light and the light color of the crushed dolomite rock on the trails, you probably won't need a flashlight, but you should take one as a precaution.
Allow enough time to get back to your car within the one-hour time limit. Don't leave valuables visible in your car. Try to familiarize yourself with the trail before the sun goes down; it can be easy to get confused in the dark.
If you just want to dip a toe into darkness, try a small preserve like Wood Dale Grove or one with options for shorter walks like Herrick Lake in Wheaton.
You don't even have to walk into woods. At Herrick Lake, Chief Wakolbinger pointed out, you can simply sit in the shelter by the lake. "It's quiet, it's beautiful and you're within a few steps of a parking lot," he said.
Among special nighttime programs coming up at area forest preserves:
"Night Owls," a one-hour hike, 7 p.m., Sand Ridge Nature Center, 15890 Paxton Ave., South Holland. Registration required; call 708-868-0606.
"Community Campfire Friday Night," 7 to 9 p.m. (repeated on Oct. 18), Greenbelt Cultural Center, 1215 N. Green Bay Road, North Chicago. Nature activities, storytelling and roasting marshmallows over an open fire. Free; bring a chair or blanket. Information at 847-367-6640.
"Stars, Stories and S'mores," an evening in the woods with a campfire, storytelling and snacks, from 6 to 9 p.m. at Thatcher Woods Pavilion, 8030 Chicago Ave., River Forest.
"Mayslake at Night," 7:30 to 9 p.m.: An opportunity to explore the woods, lakeshore and grounds around Mayslake Hall, 1717 W. 31st St., Oak Brook.
"When Darkness Falls," 6 to 8 p.m.: Waterfall Glen Forest Preserve, Darien. Soszynski will lead a hike through the dark woods explaining how to use your senses like a nocturnal predator. Free; registration required. Call 630-933-7248.
"Hike Under the Hunter's Moon," 7 p.m. Little Red Schoolhouse Nature Center, 9800 Willow Springs Road, Willow Springs. Registration required, $2 per person. Call 708-839-6897.
"Full Moon Hike," 7 p.m. Crabtree Nature Center, 3 Stover Road, Barrington Hills. Registration required; call 847-381-6592.
And those who want to experience the night woods on their own have another opportunity beginning Nov. 3 in McHenry County. Trails at two McHenry County Conservation District preserves have been outfitted with solar lights for nighttime hiking or cross-country skiing if there is snow. Through March, the trails at Hickory Grove Highlands in Cary and Pleasant Valley in Woodstock will be open till 9 p.m.