I read this for a class. It was very interesting. It is composed mostly of first-hand accounts recorded by non-Native individuals who observed events that they were unable to explain (and still cannot explain to this day outside of claims these events were made up, that the men were drugged or hypnotized, or anything but these events being real events). Some of the anecdotes were told to those recording the events; other anecdotes were recordings of first-hand experiences.
On the one hand, it offers interesting stories about Native American experiences, beliefs, and traditions, On the other hand, one's world view will impact how one interprets the stories told. The Native Americans believed the spiritual world was just as real and impactful as "the physical world", the world in which most people live, so there are very real truths and beliefs involved in and behind these stories. For most modern people, we will dismiss these stories as fantastical, farcical, and unbelievable. It is also interesting how easily we moderns can and will dismiss stories such as these as "not being true", yet these anecdotes were generally recorded by men who were otherwise well respected and believed for their training, their powers of observation, and their integrity. Not saying all of them, but a good portion of them, yet we readily dismiss events recorded by such men as being lies, tall tales, attempts to grab attention, or generally unbelievable. It is an interesting conundrum.
In any case, it was an interesting book. To be honest, I probably never would have read it were it not for my class. I may never read it again, but it was still an interesting textbook.