Supporting Science

Map of Study Area centered on Montana & Wyoming


Beginning in 2020, we set out to determine which fishes in our headwaters study area (see map) are the most vulnerable to stream warming caused by climate change. To figure this out, we expanded a stream temperature model to include eastern Montana (NorWeST: EMonSTeR), built a fish occurrence database with over 40,000 locations, and used 3 different methods to determine individual species upper thermal tolerances. We were able to do this for 38 different species or subspecies. 

By applying future climate scenarios to sites where those 38 species have been found, we determined 32 to have some vulnerability to stream warming, 22 have medium or higher vulnerability, and 18 are highly vulnerable. On the home page, you can view which previously-occupied locations are predicted to remain suitably cool or become too warm for each of the 22 species with medium or higher vulnerability to stream warming.

We are currently working to publish a paper on these findings and will update this page once that is complete.