This fact has been a major source of difficulty in our attempt to isolate social groupings among the Bannock and Shoshone. The Bannock, usually accompanied by many Idaho Shoshone, ranged east to central Montana, or into the Big Horn Basin, with the Eastern Shoshone. Part of the year, however, saw them in western Idaho and in Oregon, where they visited and intermarried with the Northern Paiute. Although we have no information on persons shifting membership from the Bannock to the Northern Paiute, such relocations no doubt took place, even if only temporarily. There are ample data, however, to document the reverse process, for Northern Paiute were continually joining the Bannock in order to take part in buffalo hunting.
The same fluidity of movement of individuals and families may be noted among the mounted Shoshone of Idaho, Utah, and Wyoming. Those buffalo hunters whom we have somewhat arbitrarily assigned to Idaho customarily wintered on the Portneuf and upper Snake rivers. But they could be found in different seasons and during various years in northern Utah, on the waters of the Bear River and east of Great Salt Lake, and in western Wyoming. Families occasionally went to the Goose Creek Mountains in the fall for pine nuts, and almost all went down the Snake River in spring and early summer to take part in salmon fishing. In all these places they interacted with and could trace kinship bilaterally to the unmounted, more permanent inhabitants.
This is true also for the so-called Eastern Shoshone. We have shown that these mounted people wintered on the Bear and Green rivers until their final establishment on the Wind River Reservation; in fact, the first Eastern Shoshone Agency was at Fort Bridger. Annual trips were made to Salt Lake City, after its settlement by the Mormons, and visits into Idaho were frequent. Moreover, Shoshone not generally associated with Washakie's leadership who possessed horses joined the latter for buffalo hunting. Evidence for this is most clear in the case of Pocatello's followers. This particular band, found at various times buffalo hunting in central Wyoming, wintering in northern Utah or southeastern Idaho, and fishing or raiding on the Snake River, is an excellent example of the social continuity between Plains and Basin-Plateau. That there was such social continuity, merging, and interpenetration indicates a common set of social understandings, of great similarity in social structure. It may be further argued that this continuity and exchange of population served in some degree to preserve a more amorphous Basin-type society among the buffalo hunters.