Although it is certain that climate change will affect the hydrology and biota of Great Plains streams, how and where these effects will be manifested is not known. This project will predict the effects of climate change on these streams by creating watershed hydrology and fish assemblage models that are both linked to watershed characteristics, then predicting changes resulting from climate change using an ensemble of general circulation models. We will identify the areas of primary conservation concern by calculating Index of Biotic Integrity values for 1,600 samples in an existing regional fish database and compare them to the areas that are most likely to experience change under future climate scenarios.