Two 21-year-old hikers were injured in a fall from a ledge at the Piney Creek Ravine Nature Preserve on May 6.
Chris Young, spokesman with the Illinois Department of Natural Resources, said that Du Quoin residents Shane Baxter and Bryce Willi were hiking with Willi's dog in the preserve.
Young said the trio were attempting to climb a wet, rocky ledge when all three fell.
In a post on the newspaper's Facebook page, Willi said his dog ran off and slipped on a lower ledge below one of the waterfalls in the preserve.
Both Willi and Baxter attempted to reach for the dog, when they slipped and all three fell six to 15 feet onto the rocky creekbed.
When emergency services arrived, they found Willi had walked back to his vehicle and he was taken to Memorial Hospital of Chester with bruises and abrasions.
Baxter also walked back toward the vehicle and was found within 250 yards of the parking lot. He was airlifted to Barnes-Jewish Hospital in St. Louis with a collapsed lung.
Conservation Police officers with the Illinois Department of Natural Resources were able to recover the dog and Willi's glasses and made arrangements to return them to the family.
The accident occurred at 3:30 p.m.
