The first record of encounter with the Mandan by Europeans is in 1738 with the visit of the French Canadian trader La Vérendrye in 1738.

The Mandans carry him into their village, whose location is unknown.

It is estimated that at the time of his visit, fifteen thousand Mandan reside in the nine well-fortified villages on the Heart River; some villages have as many as a thousand lodges.

According to Vérendrye, the Mandans at this time are a large, powerful, prosperous nation who are able to dictate trade on their own terms.

They trade with other Native Americans both from the north and the south, from downriver.

Their friendliness and willingness to trade will bring many traders and fur trappers to their villages over on the Upper Missouri in the next century.

Speakers of Mandan, a Siouan language, the people have develop a settled culture in contrast to that of more nomadic tribes in the Great Plains region.

They have established permanent villages featuring large, round, earthen lodges some forty feet in diameter, surrounding a central plaza.

While the bison is key to the daily life of the Mandan, it is supplemented by agriculture and trade.
Archaeological research suggests the Mandan people migrated from the Ohio River valley to the banks of the upper Missouri River.