<P> After the expedition had set up camp, nearby Indians came to visit in fair numbers, some staying all night . For several days, Lewis and Clark met in council with Mandan chiefs . Here they met a French - Canadian fur trapper named Toussaint Charbonneau, and his young Shoshone wife Sacagawea . Charbonneau at this time began to serve as the expedition's translator . Peace was established between the expedition and the Mandan chiefs with the sharing of a Mandan ceremonial pipe . By April 25, Captain Lewis wrote his progress report of the expedition's activities and observations of the Indian nations they have encountered to date: A Statistical view of the Indian nations inhabiting the Territory of Louisiana, which outlined the names of various tribes, their locations, trading practices, and water routes used, among other things . President Jefferson would later present this report to Congress . </P> <P> They followed the Missouri to its headwaters, and over the Continental Divide at Lemhi Pass . In canoes, they descended the mountains by the Clearwater River, the Snake River, and the Columbia River, past Celilo Falls, and past what is now Portland, Oregon, at the meeting of the Willamette and Columbia Rivers . Lewis and Clark used William Robert Broughton's 1792 notes and maps to orient themselves once they reached the lower Columbia River . The sighting of Mount Hood and other stratovolcanos confirmed that the expedition had almost reached the Pacific Ocean . </P> <P> The expedition sighted the Pacific Ocean for the first time on November 7, 1805, arriving two weeks later . The expedition faced its second bitter winter camped on the north side of the Columbia River, in a storm - wracked area . Lack of food was a major factor . The elk, the party's main source of food, had retreated from their usual haunts into the mountains, and the party was now too poor to purchase enough food from neighboring tribes . On November 24, 1805, the party voted to move their camp to the south side of the Columbia River near modern Astoria, Oregon . Sacagawea, and Clark's slave York, were both allowed to participate in the vote, so this may have been the first time in American history where a woman and a slave were allowed to vote . </P> <P> On the south side of the Columbia River, 2 miles (3 km) upstream on the west side of the Netul River (now Lewis and Clark River), they constructed Fort Clatsop . They did this not just for shelter and protection, but also to officially establish the American presence there, with the American flag flying over the fort . During the winter at Fort Clatsop, Lewis committed himself to writing . He filled many pages of his journals with valuable knowledge, mostly about botany, because of the abundant growth and forests that covered that part of the continent . The health of the men also became a problem, with many suffering from colds and influenza . </P>

Where did lewis and clark reach the pacific