North Dakota was first settled by Native Americans several thousand years ago. The major tribes in the area by the time of settlement were the Mandan, Hidatsa, Arikara, Sioux, and Chippewa. The first permanent trading post in North Dakota was established in 1801 at Pembina. American explorers Meriwether Lewis and William Clark arrived at Mandan and Hidatsa villages in 1804 near present-day Bismarck.