The first Europeans to see North Dakota came in search of furs and a water route to the Pacific Ocean. One of the first to explore the region was French Canadian Sieur de La Verendrye in 1738, when France laid claim to much of North Dakota. He visited one of the Mandan villages along the Missouri River near present-day Bismarck.

In 1803 the United States purchased this region from France in a transaction called the Louisiana Purchase. In 1804 President Thomas Jefferson sent Meriwether Lewis and William Clark to explore this territory and find a route to the Pacific Ocean. The Lewis and Clark Expedition wintered with the Mandan and Hidatsa Indians in 1804-1805. They passed through the region again in 1806 on their return from the Pacific. Lewis and Clark stayed longer in the region that became North Dakota than in any other place through which they traveled. Although many others explored after Lewis and Clark and recorded their experiences, perhaps the most valuable record was made by Prince Alexander Philipp Maximilian of Wied-Neuwied (Prussia) and Karl Bodmer between 1832-1834. The records Maximilian kept and the world famous paintings by Karl Bodmer during their winter with the Mandans at the Knife River villages provides an in-depth glimpse of Native American customs, culture and dress.

After the Lewis and Clark Expedition, the rush to establish fur trading posts on the Missouri River began. The Red River Valley fur trade in the eastern part of the state began to boom at about the same time. Beaver and buffalo furs were among the most popular items. The Red River Valley was not part of the Louisiana Purchase, but it was ceded in 1818 by the British to the United States.

During the years of the fur trade, which was dominated by the English-based Hudson Bay Company, many French traders took Chippewa or Cree wives. Their children were called Metis (meh-tee). Many Metis lived near Pembina, located in extreme northeast North Dakota, a major fur trading post and the first European settlement in North Dakota.