The Lower Grand Watershed (HUC 10280103) covers an area of approximately 1,300 square miles in west-central Wyoming. The watershed is primarily fed by snowmelt and precipitation, and is characterized by a seasonal hydrology with high flows in the spring and low flows in the late summer and fall. The watershed contains several key surface water resources, including the Green River and Fontenelle Reservoir. Snowpack in the watershed varies widely from year to year, but is generally highest in the mountainous regions of the watershed. The primary reservoir constituents in the watershed include sediment and nutrients, which can have significant impacts on water quality and aquatic ecosystems. Interesting climatic facts and trends in the watershed include increasing temperatures and changes in precipitation patterns, which have the potential to impact snowpack, hydrology, and water resources in the future.