What Is A Steelhead? Is It A Salmon Or Trout?
A steelhead is an anadromous (migratory) rainbow trout, scientific name Oncorhynchus mykiss. It is the same species as a rainbow trout, but instead of living its whole life in a river, a steelhead migrates out to the ocean (or one of the Great Lakes) to grow, then returns to the river to spawn. “Steelhead trout” is just another common name for the same fish.
What is a steelhead? After 26 years of guiding for them, I still hear the same confusion. I have heard steelhead called just “steelhead,” I have heard it called a “steelhead trout,” and while some anglers insist a steelhead is a trout, others swear it is a salmon and belongs in the salmon family. There are also plenty of local nicknames – silvers, bows, chromers, or just rainbows.
The short version: a steelhead is a rainbow trout – the sea-run or lake-run version of one. The reason people argue about salmon is that steelhead belong to the genus Oncorhynchus, the exact same genus as Pacific salmon, so they are very closely related. Below I will clear up the trout-or-salmon question, explain the difference between a steelhead and a rainbow trout, and cover their size, life cycle, and how I catch them.
Is a Steelhead a Trout or a Salmon?
A steelhead is a trout. Specifically, it is an anadromous rainbow trout, Oncorhynchus mykiss, and it is recognized by most fisheries agencies as a member of the trout family. Idaho Fish and Game puts it plainly: “Steelhead are native rainbow trout.”
So why do so many sources link it to salmon? Because steelhead sit in the genus Oncorhynchus – the Pacific salmon and trout genus – so biologically they are closer to a Chinook or Coho salmon than they are to a brown trout or a brook trout. Fisheries and Oceans Canada even notes that steelhead “were at one time considered a trout species but have been discovered by biologists to be more closely related to Pacific salmon than other trout.”
The way I explain it to clients: a steelhead behaves like a salmon (it runs from big water up into the river to spawn) but it is still a trout, and there is one behavior that settles the argument for good – see “Do steelhead die after spawning?” below.
Why Is It Called “Steelhead Trout”?
“Steelhead trout” and “steelhead” are the same fish – the extra word “trout” just reminds you that it is a trout, not a salmon. The name “steelhead” comes from the bright, steely, chrome-silver look they take on from living in saltwater or the open lake. You will also see “steelhead trout” on menus and at the fish counter, where it usually refers to farm-raised rainbow trout grown to a large size. Whether it swam up a river or came from a farm, it is the same species: Oncorhynchus mykiss.
Steelhead vs Rainbow Trout: What Is the Difference?
A steelhead and a rainbow trout are the same species. The only real difference is lifestyle. A rainbow trout that spends its entire life in a river or lake stays relatively small and keeps its colorful, olive-and-pink markings. A rainbow that migrates out to the ocean or a Great Lake – the steelhead – grows much larger and turns chrome-silver. Put the two side by side and here is how they compare:
| Trait | Rainbow Trout (resident) | Steelhead (sea/lake-run) |
|---|---|---|
| Species | Oncorhynchus mykiss | Oncorhynchus mykiss (same) |
| Lifestyle | Stays in fresh water for life | Migrates to ocean/Great Lakes, returns to spawn |
| Average size | 12-16 in, 1-3 lb | 20-25 in, 4-8 lb |
| Color | Olive-green back, bright pink stripe | Chrome-silver when fresh, pink stripe develops in-river |
| Spawns | Spring, in home stream | Spring, returns from big water |
| Can spawn more than once? | Yes | Yes |
If you want to target the resident version, I cover that in detail in my guide to rainbow trout fishing.
Steelhead Life Cycle
Juvenile steelhead spend their first couple of years in their native freshwater streams before migrating out to the ocean (or a Great Lake) to spend their adult lives. After one or two years of feeding and growing in that big water, they mature and migrate back up their home river to spawn.
That migration between fresh water and salt (or the open lake) is the one thing that separates a steelhead from a rainbow trout that stays put its whole life. That upriver run is also when we target them, because they can be found in the rivers during almost every month of the year. Depending on when the adults return, they are grouped as either winter-run or summer-run.
Note for Great Lakes anglers: our Great Lakes steelhead do the exact same thing, except they run out to the lake instead of the ocean. Same fish, same behavior, no salt required.
Winter-Run Steelhead
Winter-run steelhead enter fresh water during the colder months, from as early as November through to May. These fish are already at a fairly developed stage of maturation and spawn shortly after arriving. Winter-run fish are generally larger than summer-run fish, and often more aggressive.
Summer-Run Steelhead
Summer-run steelhead begin entering fresh water in the spring and summer, from as early as May. Unlike their winter counterparts, summer-run fish enter the river sexually immature and hold in the river for several months to finish maturing before spawning in late winter or early spring.
Despite the difference in maturity when they enter, both runs end up spawning in spring or early summer. Some rivers get both runs, and some get only one of the two.
Do Steelhead Die After Spawning?
No – and this is the detail that proves a steelhead is a trout, not a salmon. Pacific salmon die after they spawn. Steelhead do not. They are capable of spawning multiple times, dropping back to the ocean or lake to recover between runs. In practice, the mortality of that long upriver migration means only a percentage of fish actually make it back to spawn a second or third time, but the ability to survive spawning is a classic trout trait.
Steelhead Traits and How to Identify One
If you plan to spend real time chasing steelhead, it helps to tell them apart from resident rainbow trout and from salmon. There are a few subtle tells.
Body Coloration
Fresh steelhead have a chrome-colored, silvery body, versus a resident rainbow’s olive-green or blue-green back over a silvery belly. After a week or two in the river, a steelhead starts to show a pink stripe from tail to head, but it is less intense than a resident rainbow’s. Their upper body and tail are marked with black spots.
The longer they stay in the river, the darker they get, gradually losing the silver and returning to the darker, more colorful look of a resident trout.
Average Size of a Steelhead
An adult resident rainbow trout averages 12 to 16 inches and 1 to 3 pounds. Steelhead run much bigger thanks to the abundant food in the ocean and the Great Lakes. The average steelhead runs 20 to 25 inches and 4 to 8 pounds. Exceptional fish exceed 40 inches and 20 pounds, and the largest steelhead ever recorded weighed about 42 pounds – though a fish that size is extremely rare.
Diet and Feeding
Steelhead have a relatively slow attack speed, so they feed less on fast baitfish than salmon do. They will take slower prey such as sticklebacks and drifting insects rather than chasing alewives and smelt, and they also eat aquatic insects and zooplankton. Out in salt water they feed on a wider variety of prey, including squid, crustaceans, and smaller fish.
How to Tell a Male from a Female Steelhead
Like Pacific salmon, male steelhead (bucks) have a longer jawline than females (hens), with a pronounced kype – the hooked knob that forms on the tip of the jaw. A buck’s head is larger, with a convex, sloped forehead that points out at the nose, while a hen’s head flows smoothly to the tip of the nose. Bucks are taller and narrower because the body is compressed laterally, whereas a hen’s body is rounder – easiest to see when you look at the fish head-on or from above. A buck’s adipose fin can also be two to three times larger than a hen’s, and bucks have noticeably longer teeth.
Is Steelhead Trout Good to Eat?
Yes. Steelhead has firm, pink-to-orange flesh similar to salmon but with a milder, slightly more delicate flavor, and it takes well to grilling, baking, or smoking. Most of the “steelhead trout” fillets you see in stores are farm-raised rainbow trout. Wild river steelhead are a different story: in many rivers, and especially for wild fish, steelhead are managed as a catch-and-release sport fishery, so always check your local regulations before keeping one. On our home waters we release the vast majority of what we catch.
How to Fish for Steelhead
Anglers start chasing steelhead the moment the fish enter the rivers to spawn, and some also troll for them out in open water. Steelhead runs are usually triggered by rain events, water temperature, and wind direction, and the river conditions on a given day dictate everything – the bait, the setup, the leader, my casting angles, and the method I choose.
When it comes to method, the most effective ways to catch steelhead are float fishing, drift fishing, fly fishing, plunking, and bottom bouncing. I increase my odds by matching the technique to the water in front of me. After 26 years of guiding these fish, my full breakdown of which method to use and when is here: Best Way to Catch Steelhead in Rivers.
Bait matters just as much. The best steelhead baits imitate what the fish naturally eat – worms, flies, beads, and roe are my top four – and I match the bait to the season and water conditions. I break the baits down in detail here: Best steelhead baits.
Steelhead FAQ
Is a steelhead a salmon or a trout?
A steelhead is a trout – specifically an anadromous rainbow trout. It is closely related to Pacific salmon because it shares the same genus (Oncorhynchus), but unlike salmon it does not die after spawning, which is a trout trait.
What is the difference between a steelhead and a rainbow trout?
They are the same species. A rainbow trout lives its whole life in fresh water and stays smaller and more colorful. A steelhead is a rainbow trout that migrates to the ocean or a Great Lake, grows much larger, and turns chrome-silver before returning to the river to spawn.
Why is it called steelhead trout?
“Steelhead trout” is just another name for a steelhead. The word “trout” clarifies that it is a trout rather than a salmon, and “steelhead” refers to the steely, chrome-silver color it develops from living in salt water or the open lake.
How big do steelhead get?
The average steelhead is 20 to 25 inches and 4 to 8 pounds. Exceptional fish exceed 40 inches and 20 pounds, and the largest on record weighed about 42 pounds.
Do steelhead die after spawning?
No. Unlike Pacific salmon, steelhead can survive spawning and return to spawn more than once, though the difficulty of the migration means only a portion of fish actually do.
Tight Lines,
Graham
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