This project evaluates the effectiveness and efficiency of a new, dynamic genetic technology for tagging hatchery steelhead and Chinook salmon in the Snake River basin. This revolutionary technology, called Parentage Based Tagging (PBT), should provide a better tool to meet Fish & Wildlife Program objectives associated with tagging hatchery stocks, conducting hatchery evaluations and reform, and enforcing salmonid fishery management measures. This project genotypes approximately 20,000  samples annually to create PBT parental genetic baselines for hatchery steelhead and Chinook salmon in the Snake River basin.  This includes ~1,500 Fall Chinook salmon from the Lyons Ferry Fish hatchery. In doing so, it effectively, permanently genetically marks ~12 million smolts, per species, per year. This project will work closely with an existing BPA funded project (2008-907-00) to ensure that genetic marker sets used in the Columbia River basin are standardized, providing unprecedented genetic tools for managing wild and hatchery stocks in the basin: with Genetic Stock Identification techniques segregating adult wild runs by stock of origin, and Parentage Based Tagging technologies identifying the stock and age of sampled hatchery fish. In 2013, the Northwest Power Planning Council as part of the Fish Tagging Forum recommended continued funding of this technology to complete evaluation of its accuracy and ability to address key management questions under the Fish and Wildlife Program.  It is expected that project 2010-031-00 will provide written reports to Council and the ISRP in FY2018 and FY2023 on the use of this technology in the Snake River basin and the feasibility and utility of expanding it throughout the Columbia River basin.