The South Fork of the Snake River, from Palisades Dam to the confluence with the Henry's 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 (Department) 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 development and operation of fish trapping facilities 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.  The traps have been operated since 2001.  In the six years since, we have identified many limitations and obstacles to effective trapping related to the high and unpredictable runoff.  In 2007 we operated a temporary electrical weir, borrowed from another facility.  Our initial trials, combined with the successful application of this technology in the Blackfoot and Payette rivers suggests the objective of protecting, enhancing, and restoring the genetic integrity of the Yellowstone cutthroat population that spawns and rears in these streams may best be met through the use of an electrical weir in at least three of the four tributaries.  We have prioritized the four tributaries based on biological need and the applicability of the electrical barriers and will install permanent electrical weir facilities in Palisades and Pine creeks initially.  We will then investigate whether an electrical barrier or a velocity barrier will be most suited to Burns and Rainey creeks.