Cooperative Fish and Wildlife Research Units Program: Idaho
Education, Research and Technical Assistance for Managing Our Natural Resources

Idaho Project

Biotic and abiotic factors influencing population dynamics of Yellowstone Cutthroat Trout and Utah Chubs in Henrys Lake, Idaho

January 2019 - December 2021


Participating Agencies

  • Idaho Department of Fish and Game
  • Idaho Department of Fish & Game

Henrys Lake is a shallow eutrophic reservoir located in eastern Idaho near Yellowstone National Park that has long supported a renowned trophy salmonid fishery for Yellowstone Cutthroat Trout (YCT) Oncorhynchus clarkii bouvieri. Although the fishery remains popular, several concerning trends have been observed in the last decade. In particular, catch rates and body condition of YCT have declined notably in recent surveys and other recent work suggests concerning changes in growth, mortality, and size structure. Collectively, these observations imply that abiotic and(or) biotic characteristics of Henrys Lake are becoming less favorable for YCT.