Side by Side

Coho Salmon Oncorhynchus kisutch

Typical: 20–26 in, 4–8 lb

Quickest tell: Coho has a WHITE gum line (the reliable tell) with tail spots on the upper lobe only; Chinook has a black mouth WITH black gums and spots on both tail lobes; steelhead has a fully white mouth and gums.

• Chrome silver with a metallic blue-green back
• Black spots on the back and the UPPER lobe of the tail only
• Dark/gray mouth interior but a WHITE gum line at the tooth bases
• 12-15 anal fin rays
• Broad, only slightly forked tail
• Typically smaller and slimmer than a Chinook

Full Coho Salmon guide — season, gear and rules →

Steelhead Oncorhynchus mykiss

Typical: 24–30 in, 5–10 lb

Quickest tell: A white mouth AND white gums with spots radiating across the whole tail separate a steelhead from coho (dark mouth, white gums, spots on the upper tail lobe only) and chinook (black mouth and black gums).

• Bright chrome-silver sides, white belly
• Small black spots scattered over the back, dorsal, and entire tail (both lobes)
• Squared tail; 8-12 anal fin rays (fewer than salmon)
• Faint pink-red lateral band (bright on resident/mature fish)
• White mouth and white gums inside
• Small head relative to a same-size Chinook

Full Steelhead guide — season, gear and rules →

When Each Is Running July — current month highlighted

Where Coho Salmon and Steelhead Overlap

Both run in Great Lakes — that is where telling them apart actually matters.

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