Washington State Fish

Steelhead Trout

Washington State Fish - Steelhead Trout

(Salmo gairdneri)
(Oncorhynchus mykiss)

Adopted on March 18, 1969.

The steelhead trout, (Oncorhynchus mykiss,) is an anadromous fish, meaning it returns to fresh water rivers to spawn. The steelhead trout was adopted in 1969 as Washington's state fish.

Steelhead trout can reach up to 55 pounds (25 kg) in weight and 45 inches (120 cm) in length, though average size is much smaller.

They are usually dark-olive in color, shading to silvery-white on the underside with a heavily speckled body and a pink to red stripe running along their sides

Washington State Fish: Steelhead Trout

Washington State Fish - Steelhead Trout

Like all trout, the steelhead are positively separated from the various salmon species by having eight to twelve rays in the anal fin. The rainbow trout/steelhead group are then separated from the brook trout, lake trout, and Dolly Varden by the complete absence of teeth at the base of the tongue. Generally speaking, steelhead are more slender and streamlined than resident rainbow. Like rainbow, the coloration on the back is basically blue-green shading to olive with black, regularly spaced spots. The black spots also cover both lobes of the tail. The black coloration fades over the lateral line to a silver white coloration blending more to white on the stomach. Steelhead from the ocean are much more silver than the resident rainbow. On steelhead the typical colors and spots of the trout appear to be coming from beneath a dominant silvery sheen. The silvery sheen gradually fades in fresh water, and steelhead become difficult to differentiate from resident rainbow trout as the spawning period approaches.

Steelhead and rainbow lack the red slash on the underjaw characteristic of cutthroat trout, but do have white leading edges on the anal, pectoral, and pelvic fins. Spawning steelhead and rainbow develop a distinct pink to red strip-like coloration that blends along the side, both above and below the lateral line. On steelhead, the rainbow trout coloration gradually fades following spawning to the more characteristic silvery color that the fish display during their ocean journey. The distinct and beautiful coloration of steelhead during the freshwater spawning period is apparently important in regard to the mating and reproductive process. The silvery sheen and streamlined shape of ocean-bright steelhead is essential to survival in the ocean environment.

Juvenile steelhead trout are identical to rainbow trout until the period prior to their ocean migrations. Young trout and stunted adults have eight to thirteen parr marks on their sides. There are five to ten parr marks between the head and dorsal fin. Prior to migrating to the sea, juvenile steelhead become very silvery and resemble miniature adults. They are called smolt during this life phase.

Characteristics of the Steelhead Trout

Other Common Names

Coastal Rainbow Trout, Steelies

Typical Adult

Length: Up to 34 inches
Weight: Up to 8 pounds (may reach 24 pounds)
Life span: Up to 11 years


Steelhead trout are anadromous fish, which means they inhabit the Pacific Ocean and Great Lakes area except during spawning season, when they move to rivers and streams. The preferred water temperature is 55-60 °F.

Feeding Behavior

Steelhead trout feed on immature and adult insects, plankton, crustaceans, fish eggs, and small fish.

Reproductive Behavior (Spawning)

When: Late March through early June
Preferred Water Temperature: 50-60 °F
Where: Steelhead trout spawn in large, swift, boulder-strewn streams at the gravelly tail of pool or riffle at the head of a pool.
How: The female digs several nest-like depressions called "redds" and deposits eggs in each one. The adults do not guard the eggs.

Washington Law

The law designating the steelhead trout as the official Washington state fish is SECTION 1.20.045 (State fish) of the Revised Code of Washington, Title 1 (RCW GENERAL PROVISIONS) Chapter 20 (RWC GENERAL PROVISIONS) Section 1.20.040 (State fish)

RCW 1.20.045
State fish.
The species of trout commonly called "steelhead trout" (Salmo gairdnerii) is hereby designated as the official fish of the state of Washington.

[1969 c 36 ? 1.]

Taxonomic Hierarchy: Steelhead Trout

Kingdom: Animalia - animals
Phylum: Chordata
Class: Osteichthyes
Order: Salmoniformes|
Family: Salmonidae
Genus: Oncorhynchus
Species: (Salmo gairdneri) to (Oncorhynchus mykiss)

State Fishes
State Fish