The Extermination Of The American Bison

It was reprinted from a report Hornaday wrote for the Smithsonian Institution in the years 1886–87.

Extermination contains an exhaustive account of bison ecology and the story of the near-entire destruction of the bison population in the United States. The book argues for the consequent necessity of protecting the small number of bison then in Yellowstone National Park.

The book is divided into three parts. The first relates to the habits, geographical distribution, and probable population of the bison before the European settlement of North America. The second describes the extermination of the animal by industrial-scale bison hunting. It argues that the speed of extermination has been increased by unnecessary slaughter and the lack of legal protection of the bison population, among other things. The third part describes the Smithsonian's 1886 expedition to Montana to obtain specimens for the National Museum of Natural History before bison went extinct in North America. A census of the animals known to exist in captivity on January 1, 1889, showed 256 specimens in the United States and abroad.

One contemporary writer notes that a number of scholars consider Extermination to be "the first important text of the American wildlife conservation movement".

• Conservation of American bison