[25] I have in former epistles, several times spoken of the red pipes of the Indians which are found in almost every tribe of Indians on the Continent; and in every instance have, I venture to say, been brought from the Côteau des Prairies, inasmuch as no tribe of Indians that I have yet visited, have ever apprized me of any other source than this; and the stone from which they are all manufactured, is of the same character exactly, and different from any known mineral compound ever yet discovered in any part of Europe, or other parts of the American Continent. This may be thought a broad assertion—yet it is one I have ventured to make (and one I should have had no motive for making, except for the purpose of eliciting information, if there be any, on a subject so curious and so exceedingly interesting). In my +Indian Museum+ there can always be seen a great many beautiful specimens of this mineral selected on the spot, by myself, embracing all of its numerous varieties; and I challenge the world to produce anything like it, except it be from the same locality. In a following Letter will be found a further account of it, and its chemical analysis. [26] I am aware that this interesting fact may be opposed by subsequent travellers, who will find nobody but the Sioux upon this ground, who now claim exclusive right to it; and for the satisfaction of those who doubt, I refer them to Lewis and Clark’s Tour thirty-three years since, before the influence of Traders had deranged the system and truth of things, in these regions. I have often conversed with General Clark, of St. Louis, on this subject, and he told me explicitly, and authorized me to say it to the world, that every tribe on the Missouri told him they had been to this place, and that the Great Spirit kept the peace amongst his red children on that ground, where they had smoked with their enemies. [27] The medicine (or leaping) rock is a part of the precipice which has become severed from the main part, standing about seven or eight feet from the wall, just equal in height, and about seven feet in diameter.