Right road + wrong river * wrong tags on the Flickr page = Incorrect guessing.
Luke's image should go here >.>
It matches the images I have of that bridge as well.
I just guess based on the info the photographer gave me.
They thought it was Highway 2.
Perhaps it is a replacement bridge?
I think the photo you posted of this bridge is of a bridge at a different location. This structure has flat chords, while the one you posted has a parker arangement with a curved top chord.
I haven't spent a lot of time in this area so I am not quite sure which structure the photo you posted is of.
If you look at the photos from under the bridge, you can see the arrangement of the flooring system is typical of a railroad bridge, evidence of this bridge's function in its previous location.
WSDOT should be preserving this bridge not demolishing it.