of the horse resulted in some depletion of the buffalo long before the American hide hunters arrived in the West. The main body of Shoshone was encountered by Lewis and Clark on their westward trip in the Lemhi River Valley. The natives were fishing at the time, and their camps were found scattered along the stream. Camps of seven families and of one family (ibid., 3:6, 11), and another of 25 lodges (ibid., 2:175) serve as examples of the residence units met. Lewis estimated the population of the valley as 100 warriors and 300 women and children (ibid., p. 372). They possessed some 700 mounts, including 40 colts and 20 mules; this, it would seem, was not an adequate number for the needs of extensive buffalo hunting beyond the Continental Divide. The social needs of buffalo hunting evidently produced some degree of band political integration among the Shoshone. But the "principal Chief," Ca-me-ah-wait (ibid., p. 340) had only limited powers. Lewis writes (ibid., p. 370): ... each individual is his own sovereign master, and acts from the dictates of his own mind; the authority of the Chief being nothing more than mere admonition supported by the influence which the propriety of his own exemplary conduct may have acquired him in the minds of the individuals who compose the band. The title of chief was nonhereditary, and, in fact, everybody was to varying degrees a "chief," Lewis noted; the most influential of the men was recognized by the others as the "principal chief." The Shoshone had been pushed westward by the incursions of Indian tribes armed by the Canadian traders. Ca-me-ah-wait told Lewis that the Shoshone would be able to remain on the Missouri waters if equipped with firearms, but under the circumstances had to live part of the year on the Columbia waters, where they ate only fish, roots, and berries (ibid., p. 383). A few Shoshone in the Lemhi Valley had firearms that they obtained from the Crow Indians of the Yellowstone River (ibid., p. 341). The winter quarters of the Lemhi Shoshone are not described in the journals, but Lewis wrote that they remained on the Columbia waters during the time of the salmon run, from May to September, and then crossed the Divide to the Missouri waters where they spent the winter (p. 373). The presence of powerful and hostile tribes in the buffalo country forced the Lemhi Shoshone to travel in numbers. They were joined by Shoshone from other areas in the Lemhi Valley and were reinforced by more Shoshone groups and the Flathead at the Three Forks of the Missouri (p. 324).