THE ORIGIN OF THE CAHOKIA MOUNDS 



A few miles east of St. Louis, on the flat alluvial plain of the 

 Mississippi, in Madison and St. Clair Counties, Illinois, are several 

 score of mounds or low swellings from a few to a hundred feet in 

 height. For more than a century they have attracted attention 

 being in a fertile region, on a main line of travel, and near a center 

 of population. 



Many writers have described these mounds usually saying 

 that they were made by Indians. However there have always been 

 people who have thought that the mounds were just like sand bars 

 or islands in rivers. Some writers like *Worthen, Fenneman and 

 Crook. (*Geol. Surv. 111., A. H. Worthen ; U. S. G. S. Bulletin 

 No. 438, p. 12, N. M. Fenneman ; Bull. G. S. A., Vol. 29 No. 1, p. 

 80, A. R. Crook) have expressed the idea that they may be in whole 

 or in part natural. 



In early days workers had a chance to dig into the mounds 

 to see what they contain and to observe their structure, but for 

 many years past no one has had opportunity to do so. Without 

 digging accurate studies could not be made. Furthermore with- 

 out accurate levels and measurements a correct idea of the rela- 

 tions of the mounds could not be obtained. All of the maps of the 

 region which the writer has seen, leave much to be desired. The 

 topographic sheet of the U. S. Geological Survey, Saint Louis 

 quadrangle, though excellent, shows twenty foot contours only on a 

 scale of one inch to the mile while five foot contours and four inches 

 to the mile are desirable. 



Since map making is slow and expensive the writer turned to 

 the photographer and endeavored to secure aerial photographs 

 which would show the geography and topography of the region. 

 After two years of watchful working, happy fortune put in an ap- 

 pearance when through the courtesy of General Pershing, Colonel 

 Palmer arranged with the Chief of the Air Service to have photo- 

 graphs of the region taken at elevations of from one hundred to 

 fifteen thousand feet. This is another instance of the value of the 

 U. S. Army Air Service, which in war times is indispensable and 

 in times of peace makes valuable contributions to map making, to 

 exploration, to scientific discovery, to the protection of forests 

 from fire, mail service, etc. The wiser we become as a people the 

 ; more will we promote our Air Service. 



Because of the smoke from the manufacturing plants of the St. 

 Louis region and the atmospheric condition of the low lying plain, 

 it is unusually difficult to secure good photographs of the locality. 

 However, Lieutenants G. W. Goddard, photographer, and H. K. 

 Ramey, pilot, worked with such skill and persistence as to secure 

 ' splendid results in spite of unfavorable conditions. 



