From Ohio History Central
Spruce Hill Works is a monumental hilltop enclosure, similar to Fort Ancient and Fort Hill. It is unique, however, in that the enclosure wall is built entirely of stones. The people known to archaeologists as the Hopewell culture built the stone wall nearly 2,000 years ago.
The Spruce Hill Works extend for more than two-and-a-quarter miles around the edges of a dramatic 400-foot-high mesa in the Paint Creek valley. The stone walls originally may have been eight feet high in places and they enclosed 140 acres. The site overlooked a number of geometric enclosures, including the Seip Mound and Earthworks.
One of the most interesting features of the Spruce Hill Works is that several portions of the stone wall exhibit traces of intense burning. In places, the earth and surfaces of the stones have become glazed. Ohio History Connection archaeologist Emerson Greeman investigated the site in 1934 and concluded that some sort of log structure had been a part of the wall. When it burned down, the fire was so hot it turned some of the nearby stones to "slag."
The Spruce Hill Works appear similar in some ways to the Pollock Works. For a time, the stone walls may have served as a fort. Later, the enclosure may have been used for ceremonial or religious purposes.
The Spruce Hill Works currently is privately owned and is not open for visitation. The National Park Service, however, is working to add this important site to Hopewell Culture National Historical Park. Inquire at the Park for more information.