From 1930 until 1939 a study of the natural propagation of the pink salmon (Oncorhynchus gorbuscha) has been carried out at McClinton Creek, a tributary to Masset Inlet on the Queen Charlotte Islands in northern British Columbia. This stream, approximately 4 miles in length, possesses a good spawning bed, and has always had a considerable run of pink salmon. Specially constructed fences were used to assess and examine the adults migrating upstream and the fry returning to the sea. The production of fry from five spawnings has varied from 6.9 to 23.8 per cent of the possible egg deposition, i.e., the number of eggs calculated to be contained in all the females released above the weir. The loss of 76.2 to 93.1 per cent may be due to many factors, among the most important of which are the climatic conditions as they affect the water height, velocity, etc., during the stages from spawning to fry migration, and predators as they prey upon the adult salmon, the eggs and the fry. It is suggested that the number of fish or the number of eggs deposited may have an effect on the production efficiency. Data on the marine portion of the life history will not be discussed until further information is obtained on the migrations in the sea.