Some Mandan say they originated underground near the ocean and migrated from the point where they reached the earth's surface to their historic location on the Missouri River. Other Mandan say they were created on the Missouri River and were living there when the migrants joined them. The Mandan were closely affiliated with the Hidatsa and maintained trade relations with many other tribes of the northern plains. The Assiniboine, Cree, Arikara, and Crow were frequent visitors to the villages, and the Cheyenne, Yanktonai, and Lakota (Teton) were sometimes peaceful, sometimes unfriendly, to the Mandan and their allies. The first known European contact with the Mandan occurred in December 1738 when Pierre Gaultier de Varennes, Sieur de La Verendrye, and his sons visited the villages. Not until the late 1700s are there reports of other visits. One of the best known is the 1797 visit of the Canadian explorer David Thompson. The most famous White visitors to the villages were Lewis and Clark in 1804 and 1806, George Catlin in 1832, and Prince Maximilian of Wied-Neuwied in 1833-1834.
The Mandan and Hidatsa villages on the Knife River became centers of commerce on the upper Missouri and steam-boats regularly docked there. But the Sioux and smallpox reduced the number of warriors to the point where defense became difficult, and around 1845 refugee Mandan and Hidatsa moved upriver to establish Like-a-Fishhook Village. In 1862, the Arikara moved into the village, where the three tribes lived until the early 1880s, when government officials convinced them to move to ranches scattered across the Fort Berthold Reservation.