The Miamisburg Mound is one of the best known major prehistoric features in Ohio and one of the largest mounds east of the Mississippi River. As a result of excavations, its height has been reduced to approximately 70 feet. Its circumference is 877 feet, with a base that occupies about one and a half acres. In the early days of the settlers at Hole's Station, now Miamisburg, the mound was densely covered with tall trees, and a large maple tree was growing from the top.