Spirit Mound(near Vermillion, South Dakota)
24th August Friday 1804
"...in an imence Plain a high Hill is Situated, and appears of a Conic form and by the different nations of Indians in this quarter is Suppose to be the residence of Deavels. that they are in human form with remarkable large heads and about 18 Inches high, that they are Very watchfull, and are arm'd with Sharp arrows with which they Can Kill at a great distance; they are Said to Kill all persons who are So hardy as to attempt to approach the hill;...."
The above quote is taken directly from the Gary Moulton, University of Nebraska version of the Lewis and Clark Journals.