The winter camp broke up in February or March, and the spring buffalo hunt was then launched. This was a collective venture, as opposed to the sporadic and individual hunting that went on during the winter. Informants were extremely vague in saying whether all the winter camp went on the spring hunt together or whether they broke up into parties. Shimkin states that the Shoshone split into four bands when buffalo hunting (p. 247). Some of my own informants, however, said that all hunted in one group under Washakie. Others said that there were several chiefs, and each took his people where he chose. The buffalo in springtime were not of good quality, and the lean, tough meat was considered very inferior to the fat meat obtained in the fall. Informants said that the chief purpose of the spring hunt was to obtain hides for tipis (and all the other uses to which buffalo hide was put) and to get fresh meat. The spring hunt was generally pursued in the Big Horn Basin, although there were buffalo in the Wind River Valley itself, which were also hunted. Although the former locale is most frequently mentioned, it should be assumed that the migratory habits of the buffalo imposed some variability. After the spring hunt, the Shoshone reconvened in Wind River Valley and in June held their Sun Dance. This was a period of general gathering and involved visits of people from other areas. After the Sun Dance was concluded, the participants withdrew from the valley lands and retired to the Green River country and the mountains until the autumn buffalo hunt. At this time, the larger buffalo-hunt and Sun Dance group broke into small units and scattered in several directions. Shimkin maps some of the trails followed by the summer hunting parties (p. 249). Although there was considerable deviation from the trails he indicates, they show a penetration of the Yellowstone and Jackson Hole country, the Owl Creek Mountains, and the Green River and Bear River regions. Shimkin's chart of the yearly subsistence cycle shows June and July as a period of intertribal rendezvous while August and early September were spent in family groups (p. 279). My informants indicated that small groups of families were the essential social and economic units from June to September; the trade rendezvous held in the Green River country ended by 1840. Some Shoshone said the summer group consisted of only one tipi, while others claimed that this was a post-reservation pattern. In earlier times, it was said, the need for security from attack caused groups of from six to ten tipis (this figure is highly uncertain) to travel together. These summer groups were probably the most stable and cohesive units in Eastern Shoshone society, although there was a good deal of interchange of members.