This 268-acre preserve protects one of the most spectacular dolomite and limestone gorges in the state. Registered as a National Natural Landmark in 1968, Clifton Gorge encompasses a 2-mile stretch of the Little Miami State and National Scenic River, just east of John Bryan State Park.
Geologically, it is an outstanding example of interglacial and post-glacial canyon cutting. At one point, the river funnels through a deep, narrow channel, which was apparently formed by the enlarging and connecting of a series of potholes in the resistant Silurian dolomite bedrock. In other sections of the gorge, cliff overhangs have broken off forming massive slump blocks scattered along the valley floor.