From Ohio History Central
Ash Cave is part of the Hocking Hills State Park near Logan, Ohio. The cave is one of Ohio's most popular natural history attractions.
Ash Cave is located in a gorge of Black Hand Sandstone. The gorge extends approximately one-quarter mile. Thousands of years of erosion, principally caused by glaciation and a tributary of Queer Creek, which flows through the gorge, resulted in the cave. Sandstone is a very porous substance and much more susceptible to erosion than many other types of rocks. Ash Cave is the largest recess cave in Ohio. Water erosion created a recess in the sandstone that is approximately seven hundred feet long, one hundred feet deep, and ninety feet high. A small waterfall falls several hundred feet into the gorge at the front of Ash Cave.