Hell Gap is a deeply stratified archaeological site located in the Great Plains of eastern Wyoming, approximately thirteen miles north of Guernsey, where an abundant amount of Paleoindian and Archaic artifacts have been found and excavated since 1959. This site has had an important impact on North American archaeology because of the large quantity and breadth of prehistoric Paleoindian and Archaic period artifacts and cultures it encompasses. It was designated a National Historic Landmark in 2016.