Dated to 80 AD-550 AD, the Middle Woodland Indians used this area continuously for nearly 500 years. The structures built here are similar to the structures built in Ohio among the Hopewell People. It is believed that Old Stone Fort was a sacred site but no evidence has been found to connect it with funerary rituals that are prevalent at some Hopewell sites. The old Stone Fort is an ancient celestial observatory as the original entrance to the Fort marks the summer solstice exactly.
Old Stone Fort State Archaeological Park