Steelhead have a bluish-gray back and upper sides and bright, silvery lower sides, with a crisp separation between the two colors. The upper halves of their bodies are heavily speckled with small black spots. Their tail fin is completely covered with spots and may be squared or slightly forked. The interior of the steelheads mouth is white. The body is more elongate than other types of rainbow trout, and they are fast, strong swimmers.
Adult steelhead feed on squid, euphasid, amphipods and fish. While young, steelhead feed on insects, copepods, amphipods and other crustaceans, as well as other small fish.
Steelhead are native to the Pacific Ocean, but travel to inland streams and rivers spanning from southern California to southern Alaska during spawning runs. During this migration the steelhead may be found as far as inland as Idaho and Montana. They have also been successfully introduced to the Great Lakes region and its tributaries, as well as other freshwater lakes and rivers.
Steelhead are anadromous, living in both fresh water and salt water. In fresh water, they prefer temperatures below 70 F and can tolerate temperatures anywhere from 32 to 80 F. They require clean spawning rivers and prefer the faster running parts of those streams.
- Steelhead are the state fish of Washington.
- For every 100 young steelhead entering the ocean, only 5 to 10 will survive to return to their natal river or stream to spawn.