FreeFishTrout species: how to tell them apart
How to identify rainbow, brown, brook, cutthroat and lake trout and steelhead, where each lives, and the water temperatures they prefer.
Knowing which trout you're after helps you choose where to fish and what to use, and it matters for regulations: many waters have different limits for each species. Here's how to tell the common North American trout apart.
Rainbow trout
- Look for: a pink to red stripe along the side, small black spots over the back, sides and a spotted tail. Body color ranges from silver to olive.
- Where: native to the Pacific drainages, now stocked across the country in rivers and lakes.
- Behavior: often found in faster riffles and runs. Generally less wary than browns, and readily eat nymphs, eggs and dries.
- Water temperature: most active around 50–62°F; stressed above 68°F.
Steelhead
- Look for: a larger, chrome-bright rainbow trout, sometimes with only a faint stripe. Steelhead are rainbows that migrate to the ocean or the Great Lakes and return to rivers to spawn.
- Where: Pacific Northwest and Great Lakes tributaries, mainly fall through spring.
- Behavior: fish on the move; swung flies, egg patterns and nymphs work. Regulations are often strict.
Brown trout
- Look for: a golden-brown to buttery body, large black spots and red or orange spots with pale halos. The tail has few or no spots.
- Where: introduced from Europe and now widespread in rivers across the northern US and the West.
- Behavior: the wariest trout. They hold near cover such as undercut banks and logjams, feed heavily at low light, and big ones hunt other fish. Streamers at dawn and dusk are a classic big-brown tactic.
- Water temperature: tolerates slightly warmer water than other trout; most active around 52–65°F.
Brook trout
- Look for: a dark green back with pale, worm-like (vermiculated) markings, red spots with blue halos on the sides, and lower fins with a striking white leading edge. Technically a char, not a true trout.
- Where: native to the East and upper Midwest, in small, cold, clean, spring-fed streams and ponds. Stocked in some western lakes.
- Behavior: eager and opportunistic; they take small dries, nymphs and spinners. Often small in streams, but beautiful.
- Water temperature: needs cold water, about 50–60°F, and struggles above about 66°F.
Cutthroat trout
- Look for: a red or orange slash under the lower jaw, with spots that get heavier toward the tail. Several subspecies vary in color.
- Where: native to the West, from coastal streams to Rocky Mountain rivers and lakes.
- Behavior: often eager to rise to dry flies and terrestrials, which makes them great dry-fly fish.
Lake trout
- Look for: a gray to greenish body covered in pale spots and a deeply forked tail. Also a char.
- Where: deep, cold, clear lakes in the northern US, Canada and the Great Lakes.
- Behavior: shallow right after ice-out and in the fall, then deep below the thermocline in summer. Most are caught jigging or trolling, but streamers work near the surface early in the season.
- Water temperature: prefers about 45–55°F.
Quick ID chart
| Species | Spots | Key mark |
|---|---|---|
| Rainbow | Black spots, spotted tail | Pink-red side stripe |
| Brown | Black and red spots with halos | Few tail spots, golden body |
| Brook | Red spots with blue halos | Worm-like back markings, white-edged fins |
| Cutthroat | Black spots, heavier toward tail | Red-orange slash under the jaw |
| Lake | Pale spots on dark body | Deeply forked tail |
Why it matters
Regulations often differ by species, especially for native trout like brook and cutthroat, which may be catch-and-release only in some waters. When you're unsure, release the fish. In FreeFish, choosing a specific trout species under Today's target tailors the What to throw advice, and the map's Trout streams layer shows state-rated trout water in several states.
Next: learn to read the water in trout fishing in streams, or start with fly fishing basics.