Geologic History. The Rocky Fork Gorge features dolomite cliffs nearly 400 million years old, their ledges forming natural hanging gardens. The region also contains one of Ohio’s densest cave systems, with 23 caves that shelter bats, rare isopods, and other cave-adapted species.

Other dramatic formations include massive slump blocks like Steamboat Rock and the Three Sisters, as well as the cliff face known as the “Lady of the Gorge,” softened with ferns. Together, these features showcase the Highlands’ geologic wonders and continue to inspire visitors today.

The Highlands Nature Sanctuary sits at a rare geological crossroads where six major landforms converge: glaciated and unglaciated terrain, sandstone and shale, dolomite and limestone, and the western plateau blending into Appalachian hill country. This meeting of worlds has created one of Ohio’s most biodiverse landscapes.

Here, flat glaciated farmland gives way to rolling hills with rich soils that nurture dense beech–maple forests and vibrant wildflower displays. Limestone and dolomite bedrock from the west meet sandstone and shale from the east, producing dramatic contrasts in scenery and ecology. Exposed glaciated limestone—seen in only a few places in Ohio, such as Clifton Gorge—has carved striking canyons, sheer cliffs, and rare plant habitats.

Cave Country. Cave Road, located within the Highlands Nature Sanctuary, is one of Ohio's premier limestone cave regions, with 23 caves, including eight of notable size. These caves, suspended high above Rocky Fork Gorge, are remnants of ancient underground streams shaped by glacial runoff and erosion. Seven of the largest caves were originally part of Seven Caves Park. Most of these caves have been restored to their natural state, with trails and lights removed, while two of the caves remain open seasonally from July 1st until November 15. These caves are critical habitats for bats, cave-adapted invertebrates, and rare species like the Frost Cave isopod. Preserving the caves and surrounding lands safeguards these ecosystems and Ohio’s rich geological history.

Dense Wildflower Displays. The Highlands Nature Sanctuary boasts one of Ohio’s most spectacular wildflower displays, thanks to its unique geology. Alkaline-loving plants thrive here, including Columbine, Wood Poppy, Miterwort, Snow Trillium, and Sullivantia—the latter two are rare in Ohio. In peak spring bloom, trails are lined with carpets of Large-Flowered Trillium, most famously at the “Trillium Pyramid” along the Valley of the Ancients Trail near the Appalachian Forest Museum.

A particularly fascinating plant of the region is the American Colombo. Found in small colonies in sunny woodland openings above the gorge, this large, basal-leafed species has earned local nicknames such as “Century Plant” or “Wild Cabbage.” True to its reputation, the plant takes up to 30 years to bloom. When it does, a towering stalk—rising 5 to 6 feet above the leafy rosette—bears hundreds of yellow-green, lily-like flowers. After this rare and dramatic display, the plant completes its life cycle and dies.

Wildlife.