Note 88 — Chapter II

Foster, pp. 172–3, remarks: “Squier and Davis hastily stated that none of these works occupied the alluvial bottoms (an error which Mr. Squier subsequently corrected), and from this statement the most erroneous conclusions as to their antiquity have been drawn. There is nothing to indicate but that those works were constructed after the surface had assumed its present configuration, and that the climate had become essentially as it is now. That they should not occur as abundantly on the bottoms as on the river terraces is not to be wondered at, when we consider the great fluctuations of the Mississippi and its tributaries. The extreme range between low and high water of the Upper Mississippi at its mouth is thirty-five feet; that of the Missouri at its mouth about the same; and that of the Ohio at Louisville, forty-two feet. Hence, during the flood time a greater portion of the bottom lands are subject to overflow, and it would be natural for the Mound-builders to shun such situations. Where the immediate valleys lie above high water, we find their works. Of this the ‘American Bottom’ is a notable instance.”