Not only does Major Long, in the context of a brief, chronological, and no-nonsense journal, vividly describe the geographical features, flora, fauna, and residents along the Mississippi River between St. Louis and present-day Minneapolis (along with several interesting detours up tributaries) circa 1817, he also gives a thorough military critique of every significant Fort along the way, and demonstrates great interest in the native tales and unique curiosities he comes to encounter.
With regard to the lattermost - hold onto your hats esotericians, folklorists, & conspiracy theorists - in the neighborhood of Prairie du Chien, the French village at the confluence of the Mississippi and 'Ousiconsin' [Wisconsin] Rivers, Long (clearly having demonstrated in this text itself his qualifications as a military fortification expert) describes finding ample evidence of innumerable earthen fortifications made in some earlier era, which the local Indians had no idea of the purpose of, a large, formerly violently accursed statue in a ravine along the Kickapoo Creek that local natives still make offerings of tobacco to, furthermore the occasional finding on their part of uncommonly deep graves, brass tomahawks of impossible origin, and the keeping of a faint, flickering oral tradition regarding much earlier foreign visitors that were uniformly exterminated by their tribal forefathers, and - wait for it - the skeletons of eight foot tall humans found when cellars were being dug by local whites of no small reputation.
To wit, the more I learn about (what's now) Wisconsin in the 17th, 18th, & 19th centuries, the more I feel the basic suggestion put forth by Wisconsin Death Trip yet rings true for me: that this land is possessed of unknowable horrors and fathomless darkness, visible to the observer if only one finds the obscure, unguarded sources, recorded before Civil Society had put its guard up and the banality of Reason cast the fantastic and inexplicable irretrievably down into the realm of the profane.