Wildcat Canyon Waterfall is a great hike just over an hour from Chicago. The trail leads to a 125 foot waterfall and a canyon that was carved by glacial melt waters.
If you happen to find yourself in the Chicagoland area be sure to check out the Wildcat Canyon hike at Starved Rock State Park. This is a 2 mile out and back hike from the visitor's center that leads to the largest waterfall in the park. There are two viewpoints from the top of the canyon or you can descend the stairs to the bottom and explore the canyon. The waterfall tends to be at its fullest in springtime and will slow to a trickle in summer.
This trail is dog-friendly on a leash, but the metal grates on some of the stairs can be challenging for pups.