According to Mandan oral history, Double Ditch was one of seven to nine villages simultaneously occupied near the mouth of the Heart River. The Mandan population in this area probably totaled 10,000 or more during this time. The earthlodge villages were centers of trade between the Mandans, their nomadic neighbors, and later, Euroamerican traders. A massive smallpox epidemic swept the interior of North America about 1781-1782. This catastrophe was apparently responsible for the abandonment of Double Ditch and all the other Mandan villages near the Heart River. The Mandans had moved to new villages farther upriver. People of Mandan Indian ancestry live today throughout much of the Northern Great Plains. As one of the Three Affiliated Tribes, the Mandan tribal headquarters are at Fort Berthold Reservation, North Dakota. The site is open year round as there are no facilities at Double Ditch.