A modified scoop trap was designed and constructed to sample downstream-migrant juvenile salmon in the Taku River, a turbid river in southeastern Alaska. A sampling program was designed to determine the behavior of these migrants with respect to their seasonal and daily timing, the size and age composition of the various species, and the correlation between certain of these biological measurements and the physical characteristics of the environment. The length-weight relationships and condition factors of chinook, coho, and sockeye smolts were determined; differences in these relationships by week and by time of day are discussed.