Six fish cover almost every trout you will meet in North America. Four are true trout, two are char, and one of the six is the same species as another wearing a different life.
Light spots on a dark body means char. Dark spots on a light body means true trout. Brook and lake trout are char. Brown, rainbow, cutthroat and steelhead are true trout. That one rule sorts a fish in your hand before you look at anything else.
Salvelinus fontinalis
Char · Native to the east
How you know it. Pale worm-track vermiculations across a dark olive back. Red spots ringed with blue halos. A white leading edge on the lower fins.
Where it holds. Small, cold headwater streams, spring seeps and beaver ponds. Happiest from 52 to 61 F and stressed above 65.
Salmo trutta
True trout · Introduced from Europe in 1883
How you know it. Black and rust-red spots, many ringed with pale halos, on a golden-brown flank. No vermiculations, and a tail that stays nearly clean.
Where it holds. Undercut banks, log jams and deep slow pools. Tolerates water into the low 70s and feeds hardest at dusk and after dark.
Oncorhynchus mykiss
True trout · Native to the west
How you know it. A pink to red band down the flank, with black speckling scattered across the body and running in rows over the tail.
Where it holds. Faster riffles and runs with broken water on top. Comfortable from 55 to 65 F.
Oncorhynchus mykiss
True trout · The sea-run rainbow
How you know it. Chrome-bright and streamlined straight out of salt water, with the flank stripe faint or gone. The color returns the longer it holds in the river.
Where it holds. Coastal rivers on the spawning run, and Great Lakes tributaries where the fish never sees the ocean at all.
Oncorhynchus clarkii
True trout · Native to the west
How you know it. The red slash under the jaw that names the species. Spotting changes by subspecies, which is how a Yellowstone is told from a Westslope.
Where it holds. Cold western rivers and high lakes across the Rockies, the Great Basin and the Pacific slope.
Salvelinus namaycush
Char · Native to the north
How you know it. Cream to white spots on a dark grey-green body. No red spots and no stripe. The deeply forked tail is the quickest tell.
Where it holds. Deep cold lakes, colder than the rest at 46 to 52 F. Near the surface only around ice-out and in late autumn.
