Genetic analysis of coho salmon populations in the Glacier bay area of Southeast Alaska is being conducted to help understand 1) the degree of population differentiation 2) the process by which new populations are founded, and 3) the smallest viable population size. Glacier Bay provides an ideal experimental location because the rapid recession of the glaciers has exposed relatively new habitats for colonization. By comparing the genetic profiles of coho populations among streams of varying ages, more can be learned about the processes of colonization and what the minimum effective population size is. This information will be helpful to fisheries managers who need to understand the repercussions of mixed stock fisheries on salmon populations having various genetic characteristics and variation, as well as various production potentials Information on colonization is also vitally important for understanding the dynamics of restoring depleted Pacific Northwest salmon populations.