The Shoshone National Forest (Shoshone) covers 2.4 million acres of mountainous topography in northwest Wyoming and is a vital ecosystem that provides clean water, wildlife habitat, timber, grazing, recreational opportunities, and aesthetic value. The Shoshone has experienced and adapted to changes in climate for many millennia, and is currently experiencing a warming trend that is expected to accelerate in the next century. Climate change directly and indirectly affects the Shoshone's high-elevation, mountainous terrain that supports unique and sometimes rare ecological components. Several vulnerable and very responsive resources and processes on the Shoshone could interact to produce unforeseeable or undesirable ecosystem changes, highlighting the need to identify potential resource vulnerabilities and develop adaptation pathways and flexibility in resource management options. The objective of this report is to synthesize the current understanding of the paleo and historical climate of the Shoshone as a reference point, determine what future climates may look like, and what the effects of future climate may be on natural resources. This information allows for the identification of vulnerabilities and information gaps, thereby aiding the development of adaptation tools and strategies.