The book draws on a wide array of sources, including demographic, ethnographic, archaeological, epidemiological, and climatological research and records, as well as Fenn's own travels through the region.

[5] In the face of such a fleeting historical image, Fenn reconstructs the history of a sedentary and influential society that farmed extensively and was well positioned to control trading.

[3] Fenn charts the development of Mandan society over centuries, including the various challenges that often defined the long pre-contact period, such as droughts, climatic changes, and pests.

[8] As was the case with many Indigenous peoples, Fenn also charts how the impacts of European contact were felt by the Mandan long before direct contact was made, bringing new relationships and trading goods such as horses and guns, which served to bolster the Mandan position as a key trading center, as well as diseases, which ultimately undermined that position.

Their long-distance contacts ensured that the virus reached their towns, possibly again and again; once it did, Mandan numbers and population density made transmission highly likely.