Views of the 215-foot-high natural arch geological formation featuring a span of 90 feet. George Washington supposedly scaled 23 feet up one of the walls and carved his initials into it in 1750. It is comprised of grey limestone 40 feet thick. Jefferson purchased this land and 157 surrounding acres on July 5, 1774.
The long house was part of the Eastern Siouan culture and used for ceremonies and meetings. Animal skins were processed for use in clothing, blankets, and trade.
Jefferson leased out this rock shelter in 1806 for the excavation of the deposits of potassium nitrate (exhumed from the deposits of bird and bat droppings in the soil, used to make gun powder). In 1812 water was heard and an opening was blasted into a section of it known as the Lost River. A water main was attached to transport water to the hoppers and kettles used to extract the nitrate from the cave. Legend has it that in later years several attempts were unsuccessful at locating the underground channels of the lost river. Colored dyes and flotation devices have all failed to determine the source and final destinations of this subterranean river.