Some young chinook spend only a few months in the stream environment, some up to two years. Chinook seem to prefer deep, fast streams with large gravel. Adults are blue-green on the back and silvery on the sides. They may spend as many as eight years in the ocean before returning to spawn in the spring or fall. Adult spawners turn bright red on their sides and dark on their backs.
Chinook are perhaps the most economically important and valuable of all salmon.
They are highly prized by recreational, commercial and subsistence fishers alike. The National Marine Fisheries Service has recently listed four stocks of chinook salmon in the Pacific Northwest as either Threatened or Endangered. Judgment on four other stocks has been deferred until scientific disagreements have been resolved. These join three other stock of chinook already listed as Threatened or Endangered. As juveniles they have distinctive vertical bars on their sides.