Cactus Hill is an archaeological site in southeastern Virginia, United States located on sand dunes above the Nottoway River about 45 miles south of Richmond. The site receives its name from the prickly pear cacti that can be found growing abundantly on-site in the sandy soil. Cactus Hill is one of the oldest archaeological sites in the Americas. If proved to have been inhabited 18,000 to 20,000 years ago, it provides evidence supporting the Solutrean hypothesis. The site has yielded multiple levels of prehistoric inhabitance with two discrete levels of early Paleoindian activity, but this evidence has not been accepted by mainstream archeologists.
According to some archeologists, such as Dennis Stanford and Joseph and Lynn McAvoy, the Cactus Hill site furnishes evidence of a pre-Clovis population in North America. They consider Cactus Hill significant because it challenges established models of Paleo-Indian migration.
The Clovis first hypothesis is the argument that the people associated with the Clovis culture were the first widespread inhabitants of the Americas. In 1933, this view was supported by the discovery of a flint spearhead found at Clovis, New Mexico. A mammoth skeleton that was laid next the spearhead was dated as being from 11,500 BP. At the time, this was one of the earliest indications of human activity in the Americas. The evidence suggested that the introduction of the Clovis point coincided with the extinction of the megafauna on the continent; furthermore, it was believed that these people came to the Americas from Siberia through the Bering land bridge—a stretch of land that resulted from low sea levels during the Wisconsin glaciation. It is hypothesized that this allowed for migration between 14,500 and 14,000 BP. In February 2014, as published in Nature, researchers reported on the results of DNA analysis of Anzick boy, a Clovis-era skeleton, supported this theory in two directions: his DNA showed a connection to an estimated 80 percent of the Native Americans in both the Americas, as well as being connected to ancestral peoples in Siberia or northeast Asia.