Matthiessen State Park is an Illinois state park located a few miles south of the more famous Starved Rock State Park. The main entrances to both parks are located on Illinois State Route 178. The park is near Oglesby, in LaSalle County, Illinois, USA. and is named for Frederick William Matthiessen, who had originally owned the property and managed it as a private park. The park was donated to Illinois following Matthiessen's death, and was renamed in his honor in 1943.

The park is centered around a stream that flows from Matthiessen Lake to the Vermilion River. The stream has cut partway through the sandstone layers, leaving interesting rock formations and drops including the 45-foot tall Cascade Falls where the Lower Dells begin.

The day of my hike (my very first visit to the park) was very humid and the canyons cool causing a heavy mist to hang in the air throughout most of the canyon. I thought it made for some very interesting pictures. I hope you enjoy them!