settlements existed near the Great Falls for much of prehistory. Around 1600, Piegan Blackfoot Indians, migrating west, entered the area, pushing the Salish back into the Rocky Mountains and claiming the area as their own. The Great Falls of the Missouri remained in the tribal territory of the Blackfeet until Americans claimed the region in 1803. Although the discovery of the Great Falls by Native Americans is not recorded, the South Piegan Blackfeet were well-acquainted with the Great Falls by the late 18th century, and news of the cataracts had spread among native peoples as far east as central North Dakota. Lewis and Clark The United States purchased the area around the Great Falls of the Missouri from France (which claimed the area despite Native American habitation) in 1803, as part of the Louisiana Purchase. Thomas Jefferson, then President of the United States, had long desired to send an expedition into the area. Jefferson sought and won permission and funding for an expedition from Congress in January 1803. On May 14, 1804, the Lewis and Clark Expedition departed St. Louis, Missouri to map the course of the Missouri River; establish whether a river route to the Pacific Ocean existed; study the Indian tribes, botany, geology, terrain and wildlife in the region; and evaluate whether British and French Canadian hunters and trappers in the area posed a challenge to American control over the region. Expedition leaders Meriwether Lewis and William Clark first learned of the "great falls" from the Mandan Indians while wintering at Fort Mandan from November 2, 1804, until April 7, 1805. The Lewis and Clark Expedition reached the Great Falls on June 13, 1805. Meriwether Lewis was the first White person to see the falls. Lewis described the encounter in a now-famous passage of his expedition diary: ...my ears were saluted with the agreeable sound of a fall of water and advancing a little further I saw the spray arrise above the plain like a column of smoke which would frequently dispear again in an instant caused I presume by the wind which blew pretty hard from the S. W. I did not however loose my direction to this point which soon began to make a roaring too tremendious to be mistaken for any cause short of the great falls of the Missouri. ... I hurryed down the hill which was about 200 feet high and difficult of