Many of the Idaho people chose not to make this long and difficult journey and found adequate fall hunting in the local mountains. A buffalo party could thus be on the move for a few days or a week, for two months or seven months, depending on the itinerary followed. Cohesion was closest during actual traveling and hunting. Winter camps were not tightly nucleated settlements of an entire buffalo party, for hunting during the winter required some dispersal. This point deserves some elaboration. Shimkin has stressed the inadequacy of buffalo hunting for a complete winter subsistence (Shimkin, 1947_a_, p. 266) and this is borne out by the testimony of our informants also. Buffalo meat no doubt supplied the margin of survival, but considerable dependence was placed on elk, deer, moose, rabbits, and other animals during the winter. A very large and compact winter camp would soon exhaust the game in its immediate vicinity. Moreover, the winter location had to be in places where these animals could be found. Camps were thus generally located in river valleys, where wood, water, and protection from storms could be found, but in the vicinity of the high mountains inhabited by the game. Large population concentrations broke down completely during the summer. Buffalo hunting was restricted to strays and to the small timber buffalo. But the principal game was taken in the mountain country west of the Continental Divide. Large camp groups could not be adapted to the scattered resources used during this period, and people gathered mainly for reasons of defense. Summer groupings of a minimum size seem to have been positively preferred by the Shoshone, as our data from the post-reservation period indicate. This ecological adaptation and mode of social interaction with other groups had a profound effect on the structure of Shoshone society. Shimkin analyzes the fluctuations in economy and local grouping among the Wind River Shoshone and states (1947_a_, p. 280): It also strengthened the cross-currents of individualism and collective discipline: individual prestige in war honors and hunting versus united military societies and collective bison hunts.