Silver Salmon (Coho) are in all the same places, same rivers, as the King Salmon (Chinook). But the migration runs are at different times of the year.
Silvers tend to be smaller, in the 5 to 15 pound range even when mature. Kings stay at sea longer and are bigger when mature, in the 25 to 100 pound range.
Silvers are probably the best-tasting of all the salmon. The meat tends to be a deeper pink, and has a sharper more intense salmon flavor. It is probably the *perfect* fish for barbecue.
In the Puget Sound (here in WA) there is also a resident population of silvers that does *not* go all the way out to sea, but they stay in the sound for a couple of years. They don't get very big, only maybe up to the 5 to 7 pound range, but WOW are they good eating.
There's a resident school of these little guys that apparently lives just about thirty yards off the end of my dock. Catching them is like catching a big trout, and they hit nicely on a spin-cast rig. Perfect size for a large frying pan.
It is less oily than the farm raised salmon, so it doesn't fall apart like the others do. I like bbq-ing with a Ginger-Lime or Teriyaki-Sesame marinade, or even better, a Cajun Marinade!!