The Aug. 21 breach blew out the main canal bank of the Lower Yellowstone Irrigation Project, flooding a nearby sheep farm.
The mountain whitefish, which is a native species to Montana, have been found dead on the river’s east and west banks.
The first workshop will be held Sept. 20-21 in Missoula.
Wildlife officials from a government-sponsored pallid sturgeon recovery group dismissed the project’s alleged benefits for the fish as “unfounded” and “purely theoretical.”
13 sheep were killed at a ranch last week, but wildlife officials were unable to trap the bears.
Ranchers fear wildlife such as elk and bison will spread brucellosis to their livestock.