The Lower Green/Duwamish is nothing more than a drainage ditch with no full time fish habitat. When it floods you are heading out to sea. Period.
The upper river, reservoir, and other lakes are closed to the Public. Miles upon miles of forest closed off to everyone but loggers and a couple of people who win the hunting lottery.
This river is in crisis mode. Some of the residents:

Spring Chinook-extinct

Fall Chinook- The amount of natural spawners goes down almost every year. They are maintained by large hatchery plants. There is almost no in river sport fishery, they do sometimes open one section of the duwamish that is very muddy and has almost no access.

Coho- worst hatchery escapement ever this year. (2500!?) Wild fish would really like to reseed the upper reservoir and tributaries. Fish continue to get smaller. Has a decent run of “throwback jacks” I have probably thrown back a dozen hatchery jack coho that were just under 12”. Caught a 17# Back in about 2003. Those fish are rare now or gone.

Chum- the wild runs are dwindling. Abundance maintained by hatchery production.

Pink- The boom is over for now.

Sockeye- extinct

Steelhead- Threatened and currently on a path to extinction. Winter fishing is only allowed by privileged “broodstockers”

Cutthroat- I can’t speak for the upper river but lower river anadromous fish were once something I targeted, seems to be fewer these days.

Bull trout- extinct