“Is a steelhead a salmon… or a trout?”
This is a common question at the pool in the Western Cascades, where my dogs and I have spent more than 18 seasons guarding the wild summer steelhead holding there. The question is complex and I often fail to answer it very well.
First, some rainbow/steelhead taxonomy: Millions of salmon-generations ago, rainbow and cutthroat trout swam in the ocean and the rivers of the region now known as the Pacific Northwest. At that time, the Chinook, coho, chum, pink, and sockeye, as we now know them, had yet to evolve into separate species. The fish that we have come to call cutthroat trout and rainbow are the oldest species and resemble the common ancestors of the genera we have eventually named
Oncorhynchus — hooknose — the Pacific salmon and
Salmo — leaper — the Atlantic salmon...