A picket barrier with upstream and downstream fish traps was maintained on Sand Creek, a small Oregon Coast stream, during 4 upstream and 3 downstream fish runs (1946–1949), and a smaller trap was operated on a tributary during part of 1947. Two species of trout, coast cutthroat, Salmo clarki clarki Richardson, and steelhead, Salmo gairdneri gairdneri Richardson, and two species of Pacific salmon, the coho salmon, Oncorhynchus kisutch (Walbaum), and the chum salmon, Oncorhynchus keta (Walbaum), made spawning runs during the fall and winter. Downstream migrations of fry and fingerlings, and of spent adult trout, occurred in the spring. Physical data on Sand Creek included water temperatures and information on occurrence and magnitude of freshets. Records on fish trapped included the numbers of salmonids in each migration, lengths, weights, sex ratios in upstream runs, loss in weight after spawning, and survival rates. The results of this experiment indicate the need for a careful study of environmental and ecological conditions in order that a trapping structure may be adapted to extremes of water levels and to the habits of all species of migratory fishes found in the stream.