Every member dollar preserves wild trout, opens public access and so much more. To learn more about how your contribution and talent can make a difference click below.
Do your part to protect this unique natural resource by joining the Henry's Fork Foundation.
Wild Trout Tracking
Studies have demonstrated that wild trout spawn very successfully in the caldera section, particularly in the Box Canyon but also in Last Chance and certain places in the Ranch as well. The river is fully seeded; what limits the population of wild trout is the ability of juvenile trout to survive their first winter. Survival is a function of habitat availability, which in turn is dictated by water.
Brown Trout Tracking Study
The HFF's Brown Trout tracking studies evaluate trout movement, migration and habitat use in the lower Henry’s Fork of the Snake River. Researchers have collected little to no scientific information about the trout populations in this part of the Henry’s Fork that has been altered by diversion dams and irrigation canals. This multi-year effort seeks to understand the factors that govern trout distribution and abundance in this section of the river.
Click here for more information.
Rainbow Trout Tracking Study
The abundance of juvenile rainbow trout in streams and rivers can be limited by a lack of suitable spawning habitat, summer rearing habitat, or overwinter habitat (Waters 1995). A study of Seasonal Survival, Movement, and Habitat Use of Age-0 Rainbow Trout in the Henry's Fork of the Snake River, Idaho concluded that although only a limited amount of spawning activity has been observed in the Henry's Fork (Mitro and Zale 2000b), the abundances of age-0 rainbow trout present during summer and autumn suggested that spawning was not a limiting factor. The abundance of age-0 trout observed through autumn also suggested that summer rearing habitat was not a limiting factor.
However, interstitial space necessary for overwinter habitat is largely confined to the river margins of Box Canyon. Consequently, overwinter survival was greatest in Box Canyon, and rainbow trout observed in other sections in autumn were absent the following spring.
Click here for Matthew G. Mitro's & Alexander V. Zale's full report.
Ecological & Restoration Projects
Adequate water flows make a variety of habitat, in particular along the river’s margins, available to young-of-the-year wild trout. Insufficient winter flows limit juvenile trout habitat, dramatically increasing mortality rates. Other factors, such as water quality, temperatures or the availability of food are not limiting factors on the Henry’s Fork. Indeed, trout grow faster in the Caldera section than they do in any other documented stream reach in the state of Idaho. The HFF radio-telemetry fish tracking has demonstrated that adult rainbow trout survive the winter well, even under adverse flow conditions.
For more information on HFF programs designed to research, restore, and protect fish habitat, click here