Mortality of bison in the area of what is now Wood Buffalo National Park was recorded in records of Fort Chipewyan for the years 1821, 1823, and 1831. There is oral tradition in the Fort Smith area that many bison died in the Slave River lowlands during one summer later in the 19th century. The records of sudden death among bison during the summer resemble features of anthrax mortality that occurred among bison in the same general area between 1962 and 1978. This suggests that anthrax may have a much longer history in the region than recognized previously.