One of the goals of the Inventory and Monitoring program of the National Park Service is to have at least a ninety-percent knowledge of the vascular plants of each park unit. The knowledge of the vascular plant flora of Yellowstone National Park is extensive with collections dating back to 1870, but most of the collecting has been focused on areas easily approached from the road system. Documentation of the high-elevation flora of the park is made more pressing within the context of global climate change. Species that are currently in restricted habitats associated with remnant ice fields and alpine areas may in the future encounter climatic conditions that could lead to a local extirpation-on a mountain, within a mountain range, or within the entire park. Documentation of the current flora is necessary as a baseline for future knowledge about floristic changes triggered by changing climate and other factors (such as mountain goats, for example).