RIVER BASIN SALVAGE PROGRAM — ROBERTS 529 



which were collected from the occupation level. The people were pri- 

 marily dependent upon large game animals for their food, but they 

 also utilized small animals, birds, reptiles, amphibians, shell fish, and 

 possibly insect grubs, as well as roots and seeds, to round out their diet. 

 Charcoal from that level at one of the sites gave a radiocarbon date 

 of 10,493 ± 1,500 yeai-s before the present. Geologic and cultural evi- 

 dence strongly indicates that the comparable occupation at the other 

 site was during approximately the same period. 



One of the Nebraska sites, the Red Smoke, proved particularly 

 significant in containing eight distinct occupation levels. IMaterials 

 from several lying just above the oldest occupation level also repre- 

 sented a hunting economy, but they are related to a widespread cul- 

 ture which has been found as far south as western Texas and north 

 and west in Wyoming and the Dakotas. Charcoal from the top level 

 in that particular horizon has given a carbon- 14 date of 8,862 ±230 

 years before the present. The bulk of the material, however, antedates 

 that particular level and indicates that the culture was present in the 

 area during the period from about 9,000 to 10,000 years ago. The 

 other site where the oldest level was present also contained a later 

 horizon with some materials comparable to those found at the Red 

 Smoke site. Evidence for the economy at that period was for a con- 

 tinued dependence on hunting but with a change to smaller types of 

 animals. The large bison apparently were not present in the area 

 during that interval, and there may have been a change in climatic 

 conditions which caused them to move elsewhere. A radiocarbon 

 date of 5,256dz350 was obtained from charcoal from that level. The 

 paleontological material from the sites is proving useful in a study of 

 the rate of evolution which has taken place in various animal forms 

 during the past 10,000 years. In some cases there apparently has been 

 no change, while in others there are marked differences between the 

 older and the more recent forms. Another important factor in the 

 evidence pertaining to the oldest occupation in two of the sites is 

 that the materials were found in a specific geologic context. The 

 latter indicates the Two Creeks interval of the late Wisconsin glacial 

 stage. 



Belonging to the same broad cultural horizon as the older levels at 

 Red Smoke was a site in the Angostura Reservoir basin in South Da- 

 kota. It was excavated by a party from the River Basin Surveys. 

 Artifacts found there indicate a heavy reliance on hunting although 

 there may have been some use of ground seeds and nuts. Bones, how- 

 ever, are virtually nonexistent in the deposits, which may bo the result 

 of a high gypsum content in the soil that caused rapid disintegration. 

 A few of the implements from that location indicate relationship to 

 some of the forms from the Red Smoke site, others to some occurring 



