Fire is important in creating and maintaining bison habitat.
In contrast, unburned areas would have been little grazed, thereby increasing fuel loads and the probability of burning. The slaughter of bison in the late 1800's may have shortened fire return intervals and increased fire severity during the early settlement period. Bison used some watersheds preferentially and the pattern of watershed use changed seasonally. In 1988, preferential grazing of recently burned watersheds persisted through the summer months. During autumn and winter of both years, bison preferred the annual and 20-year burn watersheds to watersheds that were burned every 2 or 4 years.