Visible from State Highway 6, the Dunn site consists of three earthen mounds. Mound A, the largest, has an unusual elongated oval shape and varies considerably in summit height. The northwestern portion of the mound is just over 16 feet tall, while the southeastern portion is a little over half that. Mounds B and C have been diminished by erosion and are currently less than three feet in height. In 2013, professional archaeologists excavated a portion of the northwestern slope of Mound A. They found that the mound was built in two stages - a broad flat apron topped by a long narrow second construction stage. Large amounts of structural debris were present in the upper levels of the mound slope, suggesting that a building located on the mound summit was pushed over the edge of the mound after its destruction. Pottery and other artifacts recovered from the site indicate that Native American people built the mounds during the Early Mississippi Period or perhaps a bit earlier, from ca. AD 1000-1300.