Serotype B&colon;4 was associated with the disease in bison ("Bison bison"). Bison ("Bison bison") were a dominant species. Bison bison bison"" (Linnaeus, 1758) for the plains bison (genus "Bison", species American bison). The Yellowstone Park bison herd were Plains bison (Bison bison bison). In 1691 the buffalo ("bison bison") roamed the prairies by the thousands. American bison ("Bison bison") live in river valleys, and on prairies and plains. For example, Grasslands National park brought back Bison bison for a prairie restoration. Around 5,000 years ago, "B. occidentalis" was replaced by today's smaller "Bison bison".