Technical Abstract: Response to fire differed in moderately grazed areas compared to areas protected from livestock grazing since 1936. Long-term protection from livestock grazing resulted in cheatgrass (Bromus tectorum) invasions following fire, while moderately grazed areas were not invaded. After burning, cheatgrass biomass production and density were more than 49- and 15-fold greater, respectively, in the areas protected from grazing than moderately grazed areas. These differences were still evident 14 years post-fire and demonstrate that grazing history can have significant influence on the ability of plant communities to tolerate fire. These results suggest that moderate levels of livestock grazing may be needed in sagebrush-steppe communities to protect the habitat of sage-grouse and other sagebrush-obligate wildlife species.