Archeological Investigations - Bureau of American Ethnology, Bulletin 76 #632309

If "Cave Man"—using this term to designate the predecessor of any race or tribe known to history—ever existed in the Mississippi Valley he would not find in any part of it natural features better adapted for his requirements than in the Ozark hills. But, so far, not the slightest trace of his presence has been revealed.
By careful search in the caves and rock-shelters of which the Indian known to history availed himself, extensive and interesting museum collections can be made. To find an earlier man it will be necessary to investigate caverns which he found suitable for occupancy and in which the accumulation of detritus, from whatever source, has been sufficient to cover his remains so deeply that they can not be confused with those of a later period.