Gavins Point Dam—Lewis & Clark Lake Geology, Paleontology, Archeology, History

The archeological sites adjacent to the Lewis and Clark Lake are neither abundant nor spectacular, but nonetheless, they are of considerable interest and importance to the student of the past. Two groups of burial mounds are known: the first, the Yankton Mounds Site (39YK1), consists of five low mounds on a high terrace overlooking the Missouri River. The site has been excavated by archeologists of the W. H. Over Museum, University of South Dakota, Vermillion. In one mound, the excavators found the skeletons of at least sixteen persons. Most of the bones were in a jumbled mass, suggesting that the bones had been reburied, perhaps after the bodies had been exposed on a scaffold, as was done in more recent times. The second mound group, the Larson Mounds Site (25KX8), includes at least 10 mounds, two containing burials. Nebraska State Archeological Survey excavators reported the presence of "bundle burials", possibly similar to those of the Yankton Mounds, and cord-roughened potsherds from which a typical Woodland vessel was restored. A group of burials (39YK202), discovered just below the dam, probably represents another such reburial of fleshed bodies, but a mound was lacking. Included were a number of shell beads and a group of shell "bear-claw" pendants. Such ossuaries or reburials of a group of individuals have been found elsewhere in the Central Plains; they have long been thought of as Woodland in origin.

Other archeological sites adjacent to the reservoir are restricted to deeply buried camp areas. They appear to consist of only broken animal bone, flint chips, and charcoal. One area, the Larson Deep Site (2 5KX7), situated in a small ravine within the wooded river-bluffs, contained a hearth, a small projectile point, a hammerstone, stone and bone debris, and six small cord-roughened fragments of a clay pot. Again, the assemblage indicates an occupation by Woodland peoples.

"Woodland" mound-builders, pottery-making hunters (and perhaps farmers) were once widely distributed in the eastern and central United States. In the Middle West, the Hopewellian and Effigy Mound variants are best known. Other related groups moved westward, leaving evidence in the form of widely scattered villages and camps throughout the Missouri Basin, extending as far west as the foothills of the Rockies.