Steelhead
A rainbow trout that swims to the ocean and back, the one salmon-family fish here that can spawn more than once instead of dying after a single trip.
Steelhead at a glance
Oncorhynchus mykiss STEEL-hed; Oncorhynchus mykiss is on-koh-RING-kus MY-kiss
- Type
- Fish · trout
- Diet
- Carnivore
- Size
- A steelhead can reach 30 pounds and about 40 inches, roughly as long as a baseball bat and a half. A rainbow trout of the same species that never goes to sea typically stays under 3 pounds.
- Lifespan
- Most live 4 to 6 years and, unlike Pacific salmon, some survive spawning and return to spawn again in a later year.
- Conservation
- Least concern (IUCN); Puget Sound steelhead, the population at Olympic and North Cascades, is listed Threatened by NOAA Fisheries since 2007
Eats insects, small fish, fish eggs, shrimp-like invertebrates at sea
In fresh water a steelhead grabs drifting insects and small fish the way any trout does. At sea, sometimes for one to three years, it switches to a fish-and-shrimp diet and grows far larger than the rainbow trout that stayed behind in the river.
Should you worry?
Steelhead are completely harmless to people. Because summer-run steelhead have declined sharply in Olympic's rivers, check current fishing regulations with an adult, keep any fish wet, and stay out of the redds, gravel nests, that show up near the Hoh, Sol Duc, and Queets campgrounds in May and June.
Two fish come from the same redd in a gravel bar on the Sol Duc River. Years later, one of them still lives in that same stretch of river, three pounds soaking wet, a rainbow trout by name. The other spent one to three years in the open ocean and comes back weighing up to 30 pounds. Same species, same eggs, same water. The only thing that split their lives apart is which direction each fish decided to swim.
That second fish is a steelhead, and NOAA Fisheries calls it plainly: a life-history type, not a different species, just rainbow trout that went to sea. What makes it worth separating out is what happens after it spawns. A Chinook or a coho does this once and dies, no exceptions. A steelhead can survive the whole ordeal, swim back out to the ocean, and come home again in a future year to do it all over. Olympic’s rivers carry both a winter run, which finishes growing at sea before it returns, and a shrinking summer run that comes back early and matures in fresh water while it waits out the season.
Redds show up near the Hoh, Sol Duc, and Queets campgrounds in May and June, easy enough to walk past without noticing the disturbed gravel for what it is. Puget Sound steelhead have been federally threatened since 2007, and summer-run fish especially have fallen off hard. But somewhere in that same water is a fish that has already spawned once and made it back to try again, indistinguishable from any other steelhead in the current, carrying a second chance the salmon around it will never get.
Did you know?
- A steelhead and a rainbow trout can hatch from the same nest of eggs. The only difference is which direction each fish's life took, one to the ocean, one staying in the river.
- Local rainbow trout in Olympic's rivers usually weigh 1 to 3 pounds, but a steelhead of the same species can come back from the ocean weighing up to 30 pounds.
- Both winter-run and summer-run steelhead use Olympic's rivers. Winter fish finish maturing at sea before returning, while summer fish come back earlier and mature in fresh water while they wait to spawn.
Common questions
What's the difference between a steelhead and a rainbow trout?
They're the same species. A steelhead is the version that migrates to the ocean and grows much bigger. A rainbow trout stays in fresh water its whole life and usually stays under 3 pounds.
Can a steelhead spawn more than once?
Yes, and that makes it unusual here. Pacific salmon like Chinook and coho always die after spawning once, but a steelhead can survive, swim back to the ocean, and return to spawn again in a later year.
Where can I see steelhead spawning at Olympic?
Look for redds, gravel nests, near the Hoh, Sol Duc, and Queets campgrounds in May and June.
Are steelhead endangered?
Some populations are. Puget Sound steelhead, found in Olympic and North Cascades rivers, were listed as threatened under the Endangered Species Act in 2007, mainly from habitat loss.