RIVER BASm SALVAGE PROGRAM — ROBERTS 531 



If such were the case, we may conclude that habitations of that type 

 were used. However, there are those who maintain that the rings 

 were for other purposes, and excavations thus far have not provided 

 the answer. Campsites for tlie most part are characterized by scat- 

 tered hearths containing charcoal and ashes, and by refuse deposits 

 consistmg of bits of charcoal, ashes, cut and broken animal bones, 

 chipped-stone debris, sporadic potsherds and occasional restorable 

 vessels, and other rubbish. A number of sites of that type were ex- 

 cavated in the Jamestown and Garrison Reservoir basins in North 

 Dakota, the Angostura Reservoir area in South Dakota, and the Boy- 

 sen and Keyhole Reservoirs in Wyoming. They were found to rep- 

 resent a number of different periods. In some cases they dated from 

 a millennium to a few hundred years before the beginning of the Chris- 

 tian Era. Several fall in the early part of that period. One, in the 

 Garrison area, was several feet below the remains of an earth-lodge 

 village. Other examples appeared to belong to late prehistoric times, 

 while a few represented an early contact period as was shown by the 

 presence of trade beads and fragments of metal. The potsherds oc- 

 curring in some suggested that the camps had been occupied by hunt- 

 ing groups from permanent villages along the main stem of the Mis- 

 souri. Since they obviously antedated the introduction of the horse 

 in the Plams, they indicate that the people at times made long jour- 

 neys on foot in search of, or following, game. In the main the mate- 

 rials from the campsites show the progi-ess of the people from nomadic 

 to seminomadic life with changing types of implements and differ- 

 ences in food habits resulting in part from climatic fluctuations, shift- 

 ing feeding grounds for game, and the development of agriculture in 

 tlie more permanent settlements along the Missouri proper. It is in- 

 teresting to note that bones from the trash heaps show that in the 

 earlier stages bison were the main meat supply, then smaller animals 

 and, finally, bison again. 



ROCK SHELTERS AND CAVES 



Rock shelters and caves have been excavated in a number of areas. 

 Perhaps the oldest materials from such locations were obtained from 

 two shelters in the Keyhole Reservoir basin on the Belle Fourche 

 River in Wyoming. Both of those sites contained stratified deposits 

 showing several periods of occupation. The bottom level in each cor- 

 related with an open campsite in the same area which contained mate- 

 rials representing an Archaic hunting people who were in the region 

 following the period of the early hunters but antedating the later and 

 better-known inhabitants. Charcoal from the bottom level of one of 

 the shelters gave a radiocarbon date of 2,790 ±350. The artifacts 

 from the several layers in the deposits show a progression in imple- 



