540 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1938 



have been in recent times. This is demonstrated by the heavy zone 

 of black soil that occurs in the lower levels of the deposits over most 

 of the site. The artifacts and bones are found just below or in the 

 bottom of this layer (pi. 14, figs. 1 and 2). In this respect there is 

 similarity between the Lindenmeier and other sites where the materials 

 were also present in dark-clay deposits, but in contrast to the others 

 the Lindenmeier stratum does not represent alluvial deposits: it 

 was produced by heavy vegetation. After the abandonment of the 

 location by its human inhabitants an era of erosion set in, and mate- 

 rial from the valley walls was washed down across the site. The fill 

 in the valley bottom shows that there have been several alternating 

 periods of erosion and building up between that time and the present 

 (pi. 7, fig. 2). These changes were probably induced by the lowering 

 of the water table resulting from the encroachment of small streams 

 working headward from the south and from a progressive lessening 

 of general precipitation over the area. Dr. Kirk Bryan and Dr. 

 Louis L. Ray, of the Division of Geology, Harvard University, spent 

 four seasons working on the geology of the region in an effort to 

 date the period of occupation. They attacked the problem from the 

 angle of determining the relation of the Lindenmeier Valley to the 

 various terraces of the major drainage streams of the area. This 

 correlation was established after many months of careful survey, 

 and, by the same process of tracing terraces along the main streams 

 back into the mountains, relationship with the various glacial stages 

 was demonstrated. The conclusion reached is that Folsom men 

 lived at the Lindenmeier site while glaciers still lingered in the moun- 

 tains and when the climate was wetter and colder than now. Al- 

 though the stage represented is long after the climax of the Wisconsin 

 glaciation, it is still within the Late Glacial and is good evidence for 

 the presence of men in the New World in Late Pleistocene times. 

 From present knowledge it is not possible to give a close estimate of 

 the number of years involved, but the age has been placed at from 

 10,000 to 25,000 years ago with the probability that it is closer to 

 25,000. 



Present indications are that the Lindenmeier site was not occupied 

 continuously by a large group of people. It probably was an annual 

 summer and fall camping ground visited regularly over a period of 

 years by smaller parties. That the intervals between occupations 

 were not protracted is shown by the homogeneous nature of the 

 layer in which the artifacts are found. 5 



The find at Dent, Colo., which lies some 50 miles southeast from 

 the Lindenmeier site, consisted of mammoth skeletons and two large 

 fluted points. This association is in agreement with that found by 



1 Further information on the Lindenmeier site is contained in Bryan, Kirk, 1937; Coffin, R. Q., 1937; 

 Roberts, 1935, 1936. 



