Steelhead
Steelhead (Oncorhynchus mykiss) is a freshwater and saltwater species. The first thing to check: bright chrome silver flanks on a fresh fish, with the rainbow's pink stripe faint or absent until it has been in the river a while. The look-alike to rule out is Rainbow Trout: the same species in a different life history. A resident rainbow is coloured and stream-proportioned; a steelhead is chrome and sea-built.
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| Scientific name | Oncorhynchus mykiss |
|---|---|
| Also called | sea-run rainbow, chromer |
| Water | Freshwater and saltwater |
| Group | Trout |
| Temperature | Runs and holds in cold water, feeding and moving best between 42 and 55 °F. |
How to identify a Steelhead
- Bright chrome silver flanks on a fresh fish, with the rainbow's pink stripe faint or absent until it has been in the river a while.
- Small black spots over the back and across the entire tail fin.
- A thicker wrist and heavier shoulder than a resident rainbow of the same length.
Photograph the fish and the app will name it, though it returns this species as Rainbow Trout rather than Steelhead — the same fish under the label the app uses.
Fish it is mistaken for
| Species | How to tell them apart |
|---|---|
| Rainbow Trout | The same species in a different life history. A resident rainbow is coloured and stream-proportioned; a steelhead is chrome and sea-built. |
| Coho Salmon | Coho have black gums along the base of the teeth and spots only on the upper tail lobe; steelhead have white gums and a fully spotted tail. |
Side-by-side comparisons
Read the full entry for Rainbow Trout and Coho Salmon.
Where it lives
Pacific coast rivers from California to Alaska, and Great Lakes tributaries where the run has been established. Enters rivers on seasonal runs, holding in tailouts, seams and slots.
Temperature
Runs and holds in cold water, feeding and moving best between 42 and 55 °F.
The conditions that matter
Steelhead fishing is river-condition fishing: fish move upstream on rising, dropping-and-clearing water after rain, and a run stalls in low clear flows. Water temperature sets how far and how fast fish travel and how willing they are to move to a fly. Water temperature, clarity and recent rainfall logged per fish is the entire pattern.
Global Fishing League records 18 weather and water readings against every catch automatically — tide stage, barometric pressure, water temperature, salinity, dissolved oxygen, chlorophyll, swell, current, moon phase and more, taken at your GPS position at the moment you log the fish. Over a season that turns a hunch about steelhead into a pattern you can read.
See every reading recorded with a catch, or the guides to what each reading means.
Size limits, bag limits and seasons
Size limits, bag limits, slot limits and seasons are set by your state wildlife agency — and for many offshore and migratory species by federal regulators — and on many waters they differ from the statewide rule. They also change between seasons. Check the current regulations for the exact water you are fishing before you keep a fish — we do not republish limits here, because a number that is a season out of date is worse than no number.
What the app does do is make your side of it accurate: every catch carries a length measured from the photograph, a GPS position and a timestamp, exportable if you ever need to show your work for a tournament or a record claim. It is also what a Global Fishing League entry is built from — a record that verifies itself, without publishing where you caught the fish.