the Duwamish is essentially just the Green now. it got robbed of the white by a flood in 1906, and the cedar river, along with all of the lake Washington-lake Sammamish drainage, got sent down the ship canal. lake Washington used to be 9' higher!

I recommend reading this piece to understand how the land in Seattle has fundamentally changed over the years: CHANGING SPACES
Nature, Property, and Power in Seattle, 1880-1945 by Matthew Klingle. It's pretty staggering.

Oh and while I hate Monsanto and think they should get what's coming to 'em, Boeing is majorly to blame in this situation. They've had Seattle/King County at their beck and call since the 1920s, and try to get out of any sort of blame for pollution.