We propose radio tagging 250 Chinook salmon during our annual stock assessment project on the Taku River in 2018 with the primary objective to estimate the proportion of large Chinook salmon (≥ 660 mm mid eye to fork of tail (MEF)) tagged below the border that migrate past the U.S./Canada border (ultimately generating a mark-recapture spawning escapement estimate in conjunction with the Nahlin River sonar count). Additional objectives will be to address existing questions about migration and behavior and verify a novel genetic stock identification-based run reconstruction.