Estimates of nutrient loading to the Gulf of Mexico indicate that nine states within the Mississippi River Basin are responsible for approximately 75% of all nitrogen and phosphorus delivered to the Gulf. The Mississippi Basin supports a rich assemblage of fish species; at least 25% of all species in the conterminous United States are found in the Basin. These assemblages reflect their habitats, human landscape disturbances, and fragmentation of the river network by dams. Climate also has close associations with aquatic habitat conditions and ultimately fish community composition. Climate change is anticipated to lead to additional changes in stream habitats, including changing thermal properties and flow regimes. Ultimately, such changes will affect the Gulf, underscoring the importance of addressing upstream impacts. Accounting for current condition of and future changes in streams and understanding specific mechanisms by which they are or may become impaired are essential for effective management and conservation of stream fishes and their habitats—and will translate into improvements in nutrient loading in waters delivered to the Gulf. Based on previous work initially developed for the Northeast Climate Science Center in cooperation with the U.S. Fish & Wildlife Service in the FishTail online decision support tool only for Northeast states, this project will expand management and attribution of future climate data to the entire US portion of the Mississippi River Basin to facilitate analyses that will identify changes in fish habitat that may occur with changes in climate as a next step in meeting these needs. Narrative from the funded project proposal.