Who served as the guide for Lewis and Clark during their expedition?

The guide for Lewis and Clark during their expedition was Sacagawea. She was a Shoshone woman who, along with her French-Canadian husband Toussaint Charbonneau, joined the expedition as a translator and intermediary with various Native American tribes they encountered. Her knowledge of the land, as well as her ability to communicate with different tribes, was invaluable to the success of the mission. Sacagawea's presence also helped to establish peaceful relations with indigenous peoples, as her presence with the expedition signaled that they were not a hostile group but rather friendly explorers. Her contributions were essential in navigating the vast and often unfamiliar territories encountered during the journey to explore the newly acquired western lands following the Louisiana Purchase.