fsih4brains -
There is no such thing as Chehalis sturgeon. The fish are Columbia river fish that are foraging in the Chehalis. You will see a recovery of the Chehalis fishery as the Columbia river population recovers (if it does).

White Sturgeon spawning has only been documented successfully spawning in three rivers system on the Pacific coast; Columbia, Fraser, and Sacramento systems. They do however roam quite a bit and often dip into other river systems to feed. The juvenile sturgeon don't mature until teenagers and once they reach maturity typically spawning only every 4 to 6 years. So those that go anadromous have lots of time to move about looking for foraging opportunities.

Curt