Climate change, cheatgrass, and increases in wildfire frequency are significant threats to big sagebrush rangelands. Frequent fire can provide opportunities for cheatgrass, a non-native annual grass, to colonize, resulting in negative effects for native species, increases in fire risk, and potential transitions from native shrublands to non-native grasslands. We currently know little about how cheatgrass and fire will affect big sagebrush rangelands in the future. Our objective was to assess the vulnerability of big sagebrush plant communities to changes in future climate, fire, and cheatgrass to guide conservation priorities and planning efforts. This work developed maps of projected 21st century changes in the abundance of important components of big sagebrush plant communities across the region. Results from this analysis demonstrate that climate change has strong potential to exacerbate the impacts of cheatgrass and wildfire. In the absence of wildfire, projected future declines in big sagebrush are relatively modest (Palmquist et al. 2021). In contrast, the combination of climate change and wildfire results in more substantial and widespread declines in big sagebrush, including in portions of the region that have been historically resilient to cheatgrass invasion (England et al. in prep.). In addition, our results suggest a potential shift in the composition of perennial grasses in the region from dominance by cool-season grasses, to dominance to warm-season grasses (Palmquist et al. 2021). This shift would have dramatic negative impacts on the services provided by big sagebrush ecosystems, particularly wildlife habitat value and grazing utilization. These results are designed for range-wide conservation and land treatment prioritization, and are being used in a new interagency sagebrush landscape conservation framework led by the USFWS and the Western Association of Fish and Wildlife Agencies (Doherty et al. in review).