Fort Thompson Mounds


The Fort Thompson Mounds are a complex of archaeological sites in Buffalo County, South Dakota, near Fort Thompson and within the Crow Creek Reservation. Declared a National Historic Landmark in 1964, the mound complex extends for a distance of about along the Missouri River, and is one of the largest known complex of burial mounds in the Plains region north of Kansas.

Description

The Fort Thompson Mounds are a series of low earthen mounds, extending from the eastern end of the Missouri River's Big Bend, downriver along the eastern bank, past Fort Thompson and the Big Bend Dam. They are generally located on a terrace above the river's bottomlands, roughly above the river's typical level in the early 1960s. All of these are believed to be burial mounds, which in some cases overlay older cultural materials.
The sites were known but not studied prior to the 1950s, when the United States Army Corps of Engineers began planning the construction of Big Bend Dam as part of a flood control project. Beginning in 1957, archaeologists engaged in a series of digs to understand the sites better, and to perform salvage archaeology on sites that were likely to be inundated by the waters the dam would impound. In addition to burials found in the mounds, features of habitation were also discovered. These include stone hearths, pottery fragments, and stone tools. One of the sites excavated gave radiocarbon dates of c. 2450 BCE.