The Fort Thompson Mounds are a complex of ancient
archaeological site
An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology an ...
s in
Buffalo County, South Dakota
Buffalo County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 1,948. Its county seat is Gann Valley which, at 14 people, is the least populous county seat in the United States. The county was created ...
, near
Fort Thompson and within the
Crow Creek Reservation
The Crow Creek Indian Reservation ( dak, Khąǧí wakpá okášpe, '' lkt, Kȟaŋğí Wakpá Oyáŋke''), home to Crow Creek Sioux Tribe ( dak, Khąǧí wakpá oyáte) is located in parts of Buffalo County, South Dakota, Buffalo, Hughes County, ...
. Declared a
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...
in 1964 by the US Department of Interior, the mound complex extends for a distance of about along the east bank of the
Missouri River. It is one of the largest known complex of burial mounds in the Plains region north of
Kansas
Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...
.
One of the sites excavated in the 1950s was radiocarbon dated to c. 2450 BCE, showing nearly 5,000 years of indigenous human settlement. The mounds are believed to have been constructed in the Plains-Woodland period, beginning c. 800 CE.
Description
The Fort Thompson Mounds are a series of low earthen mounds, extending from the eastern (downstream) end of the Missouri River's Big Bend, downriver along the eastern bank, past Fort Thompson and the Big Bend Dam
Big Bend Dam is a major embankment rolled-earth dam on the Missouri River in Central South Dakota, United States, creating Lake Sharpe. The dam was constructed by the U.S. Army Corps of Engineers as part of the Pick-Sloan Plan for Missouri w ...
. 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 mounds generally date from Plains-Woodland times (c. 800) and were found to contain evidence of the first pottery-making peoples in the area.][
The sites were known but not studied prior to the 1950s, when the began planning the construction of Big Bend Dam as part of a major flood control project of several dams on the Missouri River.
Beginning in 1957, archaeologists engaged in a series of digs to understand the sites better, and to perform ]salvage archaeology
Rescue archaeology, sometimes called commercial archaeology, preventive archaeology, salvage archaeology, contract archaeology, developer-funded archaeology or compliance archaeology, is state-sanctioned, archaeological survey and excavation carr ...
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.[
]
See also
* List of burial mounds in the United States
This is a list of notable burial mounds in the United States built by Native Americans. Burial mounds were built by many different cultural groups over a span of many thousands of years, beginning in the Late Archaic period and continuing through ...
* List of National Historic Landmarks in South Dakota
The List of National Historic Landmarks in South Dakota contains the landmarks designated by the U.S. Federal Government for the U.S. state of South Dakota.
There are 16 National Historic Landmarks (NHLs) in South Dakota, one of which is share ...
* National Register of Historic Places listings in Buffalo County, South Dakota
References
{{National Register of Historic Places
Mounds in the United States
Native American history of South Dakota
Archaeological sites on the National Register of Historic Places in South Dakota
National Historic Landmarks in South Dakota
Geography of Buffalo County, South Dakota
National Register of Historic Places in Buffalo County, South Dakota
Historic districts on the National Register of Historic Places in South Dakota