Juveniles migrate to the ocean the first fall after they hatch, rearing briefly in estuaries.
They rear over a broad ocean area, ranging from northern California to the Gulf of Alaska. Adults, typically 3 to 5 years old, return to fresh water in the spring, summer or fall. Spring and summer migrants prefer deep, cool pools where they hold several months before fall spawning. In Oregon, they are only in upper Columbia Basin tributaries. Little is known about the ocean distribution of Oregon's stream-rearing chinook.