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Approximately 200 years after local extinction, Wood Bison were reintroduced into the southwest Yukon in the late 1980s as part of national recovery efforts.  The Yukon population has subsequently increased from 34 to more than 1,100 animals, prompting concerns that bison may compete with other ungulates in the area, and alter pocket grasslands within the boreal forest (analogues of ice age steppe) that contain rare, endemic plant species. As a result, the Wood Bison Management Plan (2012) identifies grasslands as a focal point for vegetation monitoring. These grasslands resemble the short-grass steppe of the west-central United States, but in the Yukon they exist almost exclusively on semi-arid south-facing slopes. Under Milchunas' Generalized Model of Effects of Grazing by Large Herbivores, a decrease in diversity is expected under such conditions. Moreover, although Yukon grasslands have historically been subject to herbivory, the overall frequency and intensity of use remains unknown. In order to quantify the impact of bison on grassland composition and diversity, bison location (GPS) data, fecal samples, orthophotos, existing plant inventory data and consultation with Champagne and Aishihik First Nations were used. After surveying vegetation cover at 70 sites representing different levels of bison usage, preliminary results indicate that both richness and Shannon's Diversity Index increase with the level of bison use, and that forbs are the driver of that change. Further exploration of these results will inform ongoing management decisions and land use planning processes within the herd range and provide important information on an understudied and rare plant community believed to be analogous to Beringian Steppe communities.