Sacagawea was either 16 or 17 years old when she joined the Corps of Discovery. She met Lewis and Clark while she was living among the Mandan and Hidatsa in North Dakota, though she was a Lemhi Shoshone from Idaho. She had been taken during a raid by the Hidatsa when she was either 11 or 12, and had lived at the Awatixa (Sakakawea) Village.
While living at the Knife River Indian Villages, Sacagawea was wed to Toussaint Charbonneau. Charbonneau, who was a French-Canadian fur trader, was hired to join the Corps as an interpreter. Sacagawea was also included due to her experience with tribes and the terrain farther west. In April 1805 Sacagawea, Charbonneau, and their two-month old baby boy set out with the Corps of Discovery.
She made important contributions to the Expedition west. She helped the Corps dig roots and find other types of food and showed the men how to make leather clothes and moccasins. Her presence among the Lemhi Shoshone, her people, no doubt helped the Corps secure the horses they needed to make it across the Rocky Mountains.
Sacagawea returned to the Mandan Hidatsa Villages in 1806, while the rest of the Corps continued to St. Louis. Not much is known of her life after the Expedition, but it is generally thought that she died at Fort Manuel Lisa from putrid fever in 1812.