29 October 1804 – March 1805
16 August 1806
The nearest neighbors of the Mandan were the Hidatsa or Minitaree Indians, who lived in three villages located within two to five miles of the closest Mandan town. The Hidatsa of North Dakota were farmers and earth-lodge dwellers with a lifestyle that was similar to the Mandan. They hunted more buffalo than the Mandan, however, often joining their closest relatives – the nomadic Crow Indians – on long buffalo hunts in Montana and Wyoming. The Hidatsa were also more aggressive than the Mandan and raided other tribes for the horses they needed.
On one such raid in 1800, Hidatsa warriors captured a 12-year-old Lemhi Shoshoni girl near the Three Forks of the Missouri River. We know her as Sacagawea, and she was living at the Hidatsa village of Metaharta as the wife of French Canadian trader, Touissant Charbonneau, when Lewis and Clark met her.
The Hidatsa were also more suspicious of American intentions than the Mandan were because they had been closely allied with British fur traders from Canada for many years. Their leading chiefs waited until 15 January 1805 to visit Fort Mandan, even though Lewis and Clark had been in the area since October. The head chief of the Hidatsa, Le Borgne or "One Eye," was a feared warrior and talented diplomat allied with the Cheyenne. The Corps of Discovery learned key information about the Rocky Mountain tribes from him and his people. However, he refused to promise that the Hidsatsa would make peace with their neighbors or be loyal to the United States.
Lewis and Clark visited him again on 16 August 1806 during their return trip to St. Louis. They gave him a small boat cannon ("swivel gun"), so that he could defend the Hidatsa from raids by the Teton Lakota and other Indians who were even more hostile to the Americans.