This dataset supports a manuscript reconstructing spatial patterns of Chinook salmon in the Kuskokwim river-basin over several years from 2017-2022. These data contain the Sr87/Sr86 value of the natal origin region for samples. These can then be used alongside the assignment script to estimate a posterior density of provenance likelihood across the watershed for each individual. At the population scale, this approach allows for an estimation of the relative density of spawning habitat across the watershed through time. Alongside daily CPUE data collected from the Bethel Test Fishery (BTF) near Bethel, Alaska, this estimation allows for the exploration of spatial patterns in the basin and assessment relative to management or resource allocation as described in the linked manuscript.