Apple River Canyon State Park Professional Guide
Detailed Trail Description from our Guidebook
"To those of us from the flat farmlan ds of central Illinois, the topography of Apple River Canyon State Park is a pleasant surprise—can these bluffs and ravines really be part of the Prairie State? Amazingly, yes—this northwest corner of Illinois is something of a geologic island, having escaped the scouring of Ice Age glaciers that leveled hills and filled valleys elsewhere in the state.
The same glaciers also blocked the Apple River’s outlet, forcing it to carve a new channel southwest. The result is a rugged and picturesque canyon, with towering dolomite cliffs overlooking the clear, bubbling waters of the river below."