Mountain regions act as the world’s water towers, namely through their ability to store water in abundant snowpacks. However, over the last half century in the western United States over 90% of snow monitoring sites have shown declines in snowpack depths and earlier onset of melting. This is projected to continue and possibly accelerate into the mid-to-end of the 21st century. California’s snow-dependent basins are particularly threatened by anthropogenic climate change, which in turn could significantly affect water availability with implications for crop yields and hydroelectric power generation loads – aggravating food and energy security at a time when demand is projected to increase. Although previous studies have assessed the impacts of droughts, namely through changes in precipitation and evaporative demand on agriculture and hydropower separately, few have focused on directly linking the projected impacts of declining snowmelt on these interconnected systems. We are developing a framework that combines variable resolution Earth System Models and crop-water models to assess water supply and demand vulnerability of California’s water-food-energy nexus to changing snow regimes in the Sierra Nevada under climate change.