This site, now beneath the waters of Clark Canyon Reservoir, was one of the most significant points along the route of the Lewis and Clark Expedition. Marked on their maps as Fortunate Camp, it was the place where the expedition sought horses from Sacagawea's people, the Lemhi Shoshoni. Traveling ahead of the main party on an Indian trail, Captain Lewis first reached the site on August 10, 1805. Two days later he crossed the Continental Divide west of here and met the Lemhi Shoshoni, who, though suspicious of the white men, returned with him to meet the rest of the party on August 17, 1805. There Sacajawea was reunited with her brother, Chief Camehwait, whom she had not seen for five years. Through her, Lewis and Clark negotiated for horses and a guide, both critical for crossing the mountains to the Columbia River drainage, while promising that future trade would bring guns and ammunition important to the Shoshoni's defense against enemy tribes. In July 1806, Clark and his party returned here to recover canoes and supplies they had cached the year before in preparation for the return trip down the Missouri River to St. Louis.