Archaeologists from Ohio Valley Archaeology, Inc., assisted by volunteers, followed a magnetometry survey by excavating a trench across part of a lost coil feature at Serpent Mound. The results suggested that part of the mound had once covered this location. In 2012, Dr. Jarrod Burks of Ohio Valley Archaeology, Inc., conducted a magnetic gradient survey of Serpent Mound, a method that reveals changes in soil magnetism caused by past ground disturbance. The most notable result was the discovery of a large U-shaped feature near the Serpent’s neck that appears to represent an ancient surface buried by an embankment that was later removed. If that interpretation is correct, the original builders of Serpent Mound, or perhaps a later group, changed the mound’s design at some point in the past, for reasons that remain unknown.