Aspen ecosystems are valued because they add biodiversity and ecological value to the landscape. They provide rich and productive habitats and increase aesthetic value. Climate change poses the risk of altering and disrupting these ecosystems, and it may worsen the effects of non-climate stressors. To provide scientific information for land managers facing the challenge of helping aspen ecosystems adapt to climate change, we developed an aspen vulnerability assessment on the Uinta-Wasatch-Cache and Ashley National Forests. Literature-based information and expert elicitation are used to define (a) components of sensitivity and exposure to climate change and (b) the capacity of these ecosystems to adapt to expected changes. Aspen ecosystems benefit from fire and quickly reproduce. Yet, aspen trees are susceptible to drought and heat that is projected to become more frequent and intense in the future. Some aspen-associated plant and animal species may benefit from the expected changes in disturbance regimes and stand structure, while others may experience population reductions or stress as a result of drought and heat. Overall, vulnerability is defined as moderate because although persistence of aspen ecosystems is likely, a dynamic spatial and temporal response to climate change is expected.