The South Fork of the Snake River, from Palisades Dam to the confluence with the Henrys Fork, supports a popular and productive fishery.   Palisades Dam, a U.S. Bureau of Reclamation project, regulates flows in this reach of the river.  Flows vary considerably based on the need for irrigation water, power production and flood control.  Life history strategies of native Yellowstone cutthroat trout (YCT) include both tributary and mainstem spawning and rearing.  Rainbow trout, a non-native species, are now well established in the mainstem and are a significant threat to the genetic integrity and population viability of cutthroat trout.  In cooperation with agency and non-governmental stakeholders, the Idaho Department of Fish and Game (IDFG) has developed a three-pronged approach to insure the long-term survival of the YCT population.  These consist of flow management, an outreach program intended to encourage anglers to harvest rainbow and hybrid trout, and tributary spawner management.  

This statement of work is associated with the third component, tributary spawner management, consisting of the operation of fish trapping facilities on the four main spawning tributaries for cutthroat trout (Burns, Pine, Rainey, and Palisades creeks).  The intent of these facilities is to conserve the genetic integrity of the YCT population through the collection all upstream spawning migrants, and based on phenotypic examination, pass YCT upstream and remove rainbow and hybrid trout.  Recent modifications to all four spawning tributary fish weirs and traps have substantially increased trapping efficiencies requiring, more personnel time to hand sort fish daily.

This statement of work is also associated with ongoing research being conducted on South Fork Snake River YCT to obtain vital, yet missing pieces of information relative to YCT population dynamics, behavior, and abundance. Since 2008, IDFG has marked Yellowstone cutthroat trout captured at spawning tributary fish traps and elsewhere in the South Fork Snake River with PIT tags. Using data obtained from recapturing or re-observing PIT-tagged cutthroat, IDFG hopes to estimate survival and growth rates, ascertain spawning site fidelity, spawning and tributary residence time, general movement patterns, and generate a river-wide population estimate of Yellowstone cutthroat trout.