Anglers everywhere call all anadromous rainbow trout steelhead. After undergoing a smolting process and moving to the ocean or another large body of water, steelhead grow quickly to adulthood. When they return to their natal rivers, they are a hard-fighting and high-jumping fish, much sought after by recreational fishermen. They've been called many superlatives -- the trout on the flying trapeze, the poor man's Atlantic salmon -- and they have justly earned their reputation. There are few other fish found in fresh water that fight as hard.

Although West Coast stocks of rainbow trout may be comprised of relatively discreet populations within isolated bodies of water, their behavior and appearance are easily altered when transplanted elsewhere. A stock of rainbows that typically spend their entire lives in a stream or lake will turn anadromous if placed where environmental factors are conducive for them to do so. Biologists once classed geographically separated stocks of rainbows into different subspecies. But they now list all rainbows — migratory fish and those that do not migrate — as Salmo gairdneri.

Size and Shape

The differences in available space and diet provided by the separate environments of the alpine or stream rainbow, inland lake fish (often called kamloops), and the anadromous ocean-run or Great Lakes steelhead result in fish of different sizes.

In many stream populations individuals never exceed a pound in weight. Space is limited in this environment and insects are the usual diet. A five-pound trout from the more spacious habitat of an inland lake is often considered a trophy.

Sizes may change from lake to lake according to the available diet. Fishes with access to big meals provided by baitfish will be larger than those limited to eating plankton and Insects. In the unlimited environment of the ocean or Great Lakes, anadromous rainbows may reach weights in excess of 20 pounds on a constant diet of high protein provided by the easy-to-catch, schooling forage fish, such as smelt and alewives.

Steelhead come in a variety of shapes in their Great Lakes habitat, partly because of a mixed ancestry. Some are long, lean, and muscular, as are West Coast steelhead. Others are deeper in body. A deeper body is also the characteristic of lake rainbows (kamloops).

Click to Listen!