Extension Special Series No. 27D
The black-footed ferret may be the rarest mammal in North America. It was first described in 1851. but was not reported again for 25 years. Ever since then, the ferret has been seen only on rare occasions, and little is known of its life history and ecological requirements.
South Dakota State University
Hillman, Conrad; Linder, Raymond L.; and Service, Cooperative Extension, "Black Footed Ferret" (1979). SDSU Extension Special Series. 116.