Indigenous and non-Indigenous natural resource managers and salmon agencies in the Yukon have identified extensive knowledge gaps surrounding juvenile Chinook salmon and their use of rearing and overwintering habitats. This knowledge gap limits the ability of resource managers to establish effective freshwater conservation and protection measures for these fish. My research will address these recognized knowledge gaps by working to identify unknown rearing and overwintering habitats, as well as patterns of movements and variability in habitat use by juvenile Chinook salmon in the Yukon River watershed. This investigation will use the isotopic chemical marker strontium (Sr) and will analyze ratios (87Sr:86Sr) found in water samples and adult Chinook salmon otoliths to determine important habitats used by these fish while in the freshwater phase of their life cycle.