The most popular of all the Hocking areas is Old Man’s Cave, located on OH-664. Here at the Upper Falls, the Grandma Gatewood Trail begins its six-mile course connecting three of the park’s areas: Old Man’s Cave to Cedar Falls to Ash Cave. This same trail has been designated as part of Ohio’s Buckeye Trail as well as part of two national systems – the North Country Scenic Trail and America’s Discovery Trail.

Old Man’s Cave derives its name from the hermit Richard Rowe who lived in the large recess cave of the gorge. His family moved to the Ohio River Valley around 1796 from the Cumberland Mountains of Tennessee to establish a trading post. He and his two dogs traveled through Ohio along the Scioto River in search of game. On one side trip up Salt Creek, he found the Hocking Region. Rowe lived out his life in the area and is buried beneath the ledge of the main recess cave. Earlier residents of the cave were two brothers, Nathaniel and Pat Rayon, who came to the area in 1795. They built a permanent cabin 30 feet north of the cave entrance. Both brothers are buried in or near the cave. Their cabin was later dismantled and relocated on the nearby Iles farm to be used as a tobacco drying house.

The natural history of this region is as fascinating as the caves are beautiful. Here, in these sandstones and shales, one can read Ohio’s history from the rocks. The scenic features of the six areas of the Hocking Hills State Park complex are carved in the Blackhand sandstone. This bedrock was deposited more than 350 million years ago as a delta in the warm shallow sea which covered Ohio at that time. Subsequent millions of years of uplift and stream erosion created the awesome beauty seen today.

The sandstone varies in composition and hardness from softer, loosely cemented middle zone to the harder top and bottom layers. The recess caves at Ash Cave, Old Mans Cave, and Cantwell Cliffs are all carved in the softer middle zone. Weathering and erosion widened cracks found in the middle layer of sandstone at the Rock House to create that unusual formation.

Other features of the rock include cross-bedding, honeycomb weathering, and slump blocks. The first is noticeable as diagonal lines in the rock intersecting horizontal ones. It is actually the cross-section of an ancient sandbar in the delta and was caused by changing ocean currents. Honeycomb weathering looks like the small holes in a beehive comb. They are formed by differential weathering which comes about when water, moving down through the permeable sandstone, washes out small pockets of loosely cemented sand grains. Finally, the huge slump blocks of rock littering the streams tumble from nearby cliffs when cracks widen to the extent that the block is no longer supported by the main cliff.

Although the glaciers never reached the park areas, their influence is still seen here in the form of the vegetation growing in the gorges. The glaciers changed the climate of all of Ohio into a moist, cool environment. Upon their retreat, this condition persisted only in a few places such as the deep gorges of Hocking County. Therefore, the towering eastern hemlocks, the Canada yew, and the yellow and black birch tell of a cool period 10,000 years ago.

The AllTrails website has a description and map of a hike to Old Mans Cave.