Who served as a guide for Lewis and Clark on the expedition on the pacific?

Sacagawea, a Shoshone woman, served as a vital guide and interpreter for the Lewis and Clark Expedition. She joined the expedition in 1805, aiding the explorers with her knowledge of the terrain and local tribes. Her presence helped facilitate communication and fostered peaceful relations with Native American groups along the journey to the Pacific. Sacagawea's contributions were crucial to the expedition's success.