Andy,

I'll try not to repeat too much, but this may help you understand. Steelhead are defined as summer runs or winter runs based on the time of year they enter fresh water from the ocean. Most summer runs enter fresh water from April through October, but I've seen one as early as February.

How did I know it was a summer run since February is decidedly winter? Well, as mentioned, trout, including steelhead, are predominately spring spawners. The February summer run had never spawned, had no mature or maturing eggs in it, but had the narrowest string of egg skeins, indicating that it would not spawn for a year or more from its date of river entry.

An extension of the definition of a winter run, in addition to entering fresh water during the winter, is that they spawn in or near the season that they enter fresh water. Most winter runs enter fresh water from October to April, sometimes as late as May in rivers further north in B.C. and Alaska.

So how would you tell an October winter run from an October summer run? An October summer run normally exhibits some color, from a little to a lot. That is, it will have pink or red on its gill plates and a rosy rainbow stripe down its side. Or it could be more sexually developed, with a deeper red rainbow stripe and olive colored back, looking much like a resident rainbow trout. The October winter run, however, should be absolutely chrome, blue back, silver sides, loss scales, and white belly. If it helps, consider that all the steelhead in the Snake and mid-Columbia Rivers and their tributaries are summer runs, even tho anglers will be catching them for months to come.

Conversely, the April entering winter and summer runs will be reversed from the above, with the winter runs often showing some color, and even if they are silver bright, they show some sexual maturation in the form of a thicker belly - full of maturing milt or eggs, compared to the slimmer summer run. An April summer run is mint bright, and typically as hot a fish as you will ever hook.

Add to all the above the spawn timing of the various runs. Hatchery winter runs spawn mostly from late December to the end of January, but can spawn from late November to sometime in April. Wild winter runs spawn mostly from late March through May, but can range from January to the end of June. Hatchery and wild summer runs spawn mainly in February and March, but range from January through April and possibly May for wild ones. Confusing, isn't it? It's all part of the fun of chasing these crazy fish.

(Disclaimer: someone will likely dispute some part of the above information. I try never to say never regarding a lot of things about fish. There seems to be at least one exception to every rule; that's why I mentioned the February summer run.)

Sincerely,

Salmo g.