I believe it may depend on just how "downriver" the fish is...

I've caught steelhead that upon cleaning appear to have recently spawned and they were fine to eat. However, the absolute worst fish, I attempted to eat was a bright, but skinny appearing, hatchery steelhead out of the Bogey. The flesh turned into a paste; when cooked... Being a young, naive steelheader at the time, I got a first hand taste of a true "downriver" fish.