BOURNEVILLE: Spruce Hill remains one of the biggest mysteries in Ohio.
It is a monumental stone-walled fortress on a plateau west of Chillicothe in Ross County.
The walls around the steep-sided plateau surround 140 acres and stretch more than 2¼ miles. That’s big enough to hold 110 football fields. The plateau was once forested. Today it is a flower-filled meadow.
Spruce Hill was once hailed as a place where Celtics or Vikings may have camped and forged iron. Others called the stone walls nothing more than a natural feature.
Limited archaeological research indicates that the fortress was actually built by the Indians of the Hopewell Culture from 1,600 to 2,000 years ago.
It remains one of the most important and puzzling archaeological sites in Ohio, one of a dozen surviving hilltop enclosures built by the Hopewells. It is similar to Ohio’s Fort Hill and Fort Ancient state memorials, and the largest single enclosure the Hopewells ever built.
Spruce Hill is one of only three Hopewell hilltops surrounded by stone, not earth as was more common. It might have been a fortress, or it may have been built for religious or ceremonial purposes. It was studied and mapped in the 1800s, but it has produced few artifacts, compared to Hopewell mounds.
No one has a solid explanation for why the ancient hunter-gatherer Indians built a stone-walled fortress 2,000 years ago above Paint Creek in southern Ohio.
What you find at Spruce Hill today is very similar to and largely unchanged from the early 1800s when it was discovered by white settlers. It sits above two nearby Hopewell works, the Seip Earthworks and the Baum Earthworks, with their geometrical shapes and mounds.
Something else adds to the Spruce Hill mystery: evidence that very hot fires burned there, hot enough to melt sandstone and create slag. It is unclear how or why that happened.
There are about 30 spots along the walls with burnt, fused or glazed sandstone, vitrified soils, burnt clay and cinders. The temperatures needed to produce such effects are far hotter than normal fires.
That fact led many to speculate that the Hopewells were forging iron, although there is no evidence of that. Others theorized that Celtic and Viking colonies could have built the fires to produce iron. That theory was strongly advanced in 1948 by Captain Arlington Mallery in his book Lost America.
Today, the theory is that timbers added to the walls burned. Archaeologists have found evidence that the walls at Spruce Hill likely contained logs that were later burned. There were baked clay clumps with the impression of criss-crossing logs in them, similar to old fired forts found in Scotland and elsewhere in northern Europe.
The 270-acre site sits south of U.S. 50 about 12 miles west of Chillicothe, about 3½ hours from Akron.
It is not part of nearby Hopewell Culture National Historic Park, which includes five other sites: the Mound City Group, the Hopewell Mound Group, the Seip Earthworks, the Hopeton Earthworks, and the High Banks Earthworks.
Spruce Hill is owned by the Arc of Appalachia Preserve System, a nonprofit group, and the Ross County Parks District.
The Arc of Appalachia covers 5,000 acres in 14 preserves in southwestern Ohio. The nonprofit group manages the Serpent Mound and Fort Hill, ancient Indian archaeological ruins, for the Ohio Historical Society.
Spruce Hill is rarely open to the public, but I signed up for a ranger-guided 3½-mile hike, a once-a-year event in late September. You need a permit from the federal park service or the Arc of Appalachia office to hike Spruce Hill on your own.
About 70 hikers met on a Sunday morning at the small parking lot on Spruce Hill Road in Twin Township. We were each furnished with a copy of an old map/sketch of the walls and entrance gates from 1848.
We hiked along an old farm road that climbed through the forest to the plateau about 350 feet above.
Much of the plateau was covered by a meadow that was dominated by goldenrods and asters. A rough-hewn trail had been hacked out of the brush a few days earlier by a crew from the park service.
We hiked the entire length of the meadow to what’s called the isthmus, one of the most interesting features at Spruce Hill, said ranger Bruce Lombardo of the National Park Service, our trip leader. He took us into the woods and showed us what’s left of the rock walls, but what we saw was not impressive.
Historical descriptions and conjecture vary. Some say the walls may have been 8 feet high; others disagree. Today the rocks are scattered and it takes some imagination to picture a rock wall at all. The stones are found mostly in a band yards wide or in low heaps in the woods. The walls are largely made of small, rubble-sized stone.
Lombardo showed us what’s been described as the north gate, a rock wall with three 10-foot-wide openings. They are separated by walls that range from 120 to 240 feet long.
We moved to the second gate opening and Lombardo stood in a ditch surrounded by pawpaw trees. It was easier to picture the stone wall here. Most people would never find the gates or the walls. Lombardo’s help was essential.
The second gate is where Lombardo explained to the hiking group what is known about Spruce Hill. It has received scant scrutiny over the years, largely because it was privately owned, he said.
A team of park service archaeologists worked at Spruce Hill in 1995-1996. They found a ceramic vessel, a discarded bladelet of flint and a few other artifacts at the base of the wall, proof that the walls were made by Hopewells. That investigation also proved that the walls are largely man-made, not naturally occurring.
Lombardo said some features at Spruce Hill are similar to the Pollock Earthworks in Ohio’s Greene County, part of the Indian Mound Reserve.
On the way back on the hike, we stopped at the smaller southern gate, where the entrance trail reaches the plateau and the meadow.
A few steps off the trail led to a shallow rocky defile where one opening had been built by the Hopewells. Today it is called Gate A. You could almost make out an opening in rocks scattered and piled on both sides of the gateway.
The Hopewell Culture park was initially established in 1923 as the Mound City Group National Monument.
In 1987, the park service began considering whether Spruce Hill was significant enough to add to the federal park, as it was at risk of being developed, logged and lost. It was acquired in 2007 by the Arc of Appalachia and partners just two days before it was to be auctioned off.
Bob Downing can be reached at 330-996-3745 or email@example.com.