The process began Monday (Mar. 28) to learn what may be buried on top of the Cavanaugh Mound and possibly to learn how the mound was built.
The mound, located behind the New Liberty Baptist Church in south Fort Smith, is believed to have been constructed by Native Americans (possibly Caddo Indian ancestors) between AD 1100 and 1300.
The mound, originally about 200 feet long at the base of each of the four sides and about 40 feet tall, is a project The Archaeological Conservancy has said it will research and restore. If funding is available, the Conservancy also hopes to build a small park around the mound with signage and other exhibits that explain the historic site.
Tim Mulvihill, an archeologist with the University of Arkansas system, Jami Joe Lockhart, coordinator of the Computer Services Program for the Arkansas Archeological Survey of the University of Arkansas System, and Bob Dalton, a founding member of the Ark-Homa chapter of the Arkansas Archeological Society and Oklahoma Anthropological Society, gathered Monday morning to begin the underground mapping process.
“This (mound) is really impressive,” said Lockhart, who travels the state mapping old or historic cemeteries, pre-historic sites and historic sites. He said the mound “is easily in the top 10” of large mounds in Arkansas.
Lockhart brought three devices to map the mound — a tool that uses electrical resistance to determine what is just a few feet under the surface, and two ground-penetrating radar units.
The three spent about an hour using stakes and ropes to create a grid on the mound top. Mulvihill then used the resistance device to map the top layer. Previous research on the mound suggests there could be 12 non-Native American burial sites on the mound top.
“We leave them alone,” Mulvihill said when asked what happens if gravesites are found. “We have no plan to do anything with them.”
A 400 megahertz radar measured the mound from the top to about 10 feet down. A 200 megahertz radar measured the mound from the top to about 30 feet down.
“We may or may not get that deep here, but we do expect to see different episodes of building,” Lockhart explained.
It is believed the Caddo Indians built the mound in several phases.
Results of Monday’s scanning are expected within two weeks.
Mulvihill also hopes to soon begin work restoring the eastern slope of the mound. A large section of the mound slope was removed at some unknown time for some unknown reason. A rough estimate indicates it will take 900 cubic yards of dirt to restore the slope — or just short of 182,000 gallons of dirt.