Clifton Gorge is a feature to Ohio’s glacial past. It is a classic example of a canyon cut into dolomite and shale bedrock that dates to the Silurian Period 400 million years ago. Created by meltwater released from the retreating continental glacier some 15,000 years ago, the cool, moist gorge has maintained a diversity of native plants, such as the red baneberry bush, that are now rare elsewhere in Ohio. The Little Miami River powered grist and cotton mills, paper factories, and breweries in the gorge during the nineteenth century. In 1973 the upper gorge became a state nature preserve.

— From the Ohio Historical Marker