Kidnapped from her family at the age of twelve, then sold into marriage to a French fur trapper named Toussaint Charbonneau, sixteen year old Sacagawea has long held a place of renown in the hearts of the people of the west. Charbonneau and Sacagawea were staying in a Hidatsa village on the banks of the Missouri when the Lewis and Clark Expedition built their winter fort there in 1804. The Expedition enlisted the services of Charbonneau and his pregnant wife to serve as translators on their westward journey. The captains hoped that since Sacagawea's Shoshone tribe lived near the headwaters of the Missouri, she could help them procure horses with which to cross the Continental Divide. As they passed through Southwest Montana, Sacagawea proved her worth. She recognized the area and assured the captains that they would soon find bands of Shoshone. When they finally encountered Shoshone Indians, west of Beaverhead Rock, Sacagawea recognized her brother as the leader of the band. Sacagawea's presence eased tensions and convinced the Shoshone to provide the Expedition with horses and guides.

Sacagawea travelled from North Dakota to the Pacific and back with a newborn baby in her arms. She proved to be always cool and collected in the face of danger. Once, when a one of the Expedition's boats capsized, Sacagawea calmly scooped the captain's journal's and records out of the river. She served as an invaluable source of information, and as a peace making factor in the Expedition's encounters with Indians. Although these things cannot be downplayed, perhaps her greatest contribution was her mere presence. The presence of a woman and child on the expedition convinced the tribes they encountered of the peacefulness of their mission. Modern retellings (and to some extent Lewis and Clark's own journals) tend to portray Charbonneau as a bit of a blunderer, a fool, but all accounts, past and present, give Sacagawea universal renown.