1) Roza Dam has excellent collection facilities, and could be used to collect steelhead for broodstock for the upper Yakima population. Yet, Roza Dam is located fairly far downstream of steelhead spawning areas, so it is important to determine if there are multiple populations upstream of Roza Dam. If a collection is composed of two or more separate populations, and the mixed collection is analyzed as if it were a single randomly mating population, the distribution of genotypes given the allele frequencies observed will not meet statistical expectations.