One of the major problems in connection with water resource development in the Pacific Northwest of the United States has been safe fish passage at dams. Particular concern has been felt in regard to fish safety at dams 100 ft or more high. This concept has been perhaps the greatest factor in establishment of the basic plan for development of the Lower Columbia and Snake Rivers. Also, it may be that the apparent safety accorded to dams under 100 ft high has been an adverse factor in migratory fish protection. There is now promising evidence that successful passage can be achieved through hydraulic characteristics of the water passageways are far more significant than heights of dams. This paper reviews basic concepts of fish passage through dams and their significance with particular reference given to passage through turbines. Test procedures and summarized results of fingerling survival in passing through high speed model turbines and a prototype turbine under a 450 ft hydraulic head are furnished. The numerous data presented demonstrating a correlation of fish survival with various turbine characteristics show promise of leading to their achievement of successful passage through the high head turbines.