Anadromous juvenile salmonids (Oncorhynchus spp.) migrating through the Columbia River experience a variety of hazards that affect their survival as they migrate from freshwater rearing habitats to the ocean. Predation by native and non-native fish predators in the hydroelectric impoundments in the Columbia River has been an important factor in contributing to the total mortality of seaward migrating salmonids. The Public Utility District No. 2 of Grant County, Washington (Grant PUD), on behalf of the Priest Rapids Coordinating Committee (PRCC), has requested that the U. S. Geological Survey (USGS), Columbia River Research Laboratory, and Washington Department of Fish and Wildlife (WDFW) assist them in their efforts to evaluate the effects of native and introduced predatory fish on migrating juvenile salmon.