The Post-Apocalyptic Roadmap/Washington

Part of the Post-Apocalyptic Roadmap Project.

Seattle gets nuked. But the warhead doesn't go off until after it's plunged into the river and detonates, nearly harmlessly, underground. The radiation kills off the surrounding suburbs, but leaving the cities mostly intact. Survivors try to reestablish in bands of scavengers living high up in the tallest buildings to avoid radiation. Once the food runs out, radioactive fishing efforts in the Puget Sound lead many to eventually flee to Vancouver Island for better fishing. The Space Needle is first inhabited by a humanitarian effort, hoping to bring the local radiation down to a habitable level. Their plans crumble as a mad scientist guns down the effort and uses their research to turn the Space Needle into a giant, radioactive death ray.

Most of the world didn't notice, because it's fucking Seattle.

Outside Seattle, the Pacific Northwest rainforests absorb a lot of the radioactivity carried on the fallout-laden winds, and will eventually flush it out via the watersheds. Not, of course, before it kills many species slowly over the course of months and years through slow radiation poisoning.

The Portland bomb does similar things, except it kills a lot of people outright, and scorches flat north Portland. The people that survive scrounge the southern parts of the city or flee even farther south into unaffected Oregon state proper.

Spokane advances out to begin farming operations in the surrounding area after being cut off from outside trade for too long. Eventually, Spokane and nothern Idaho begin a profitable trade operation.

The Kennewick bomb went unnoticed, because even Seattle doesn't care about Kennewick.

One cool thing is that the ferries, which transported most of the Seattle population, were colonized by entrepreneurs looking to cash in on transport needs. When that falls through due to lack of customers (duh) the ferries become retrofitted into slow, steam-powered dreadnaughts armed to the teeth and used as a hoarding cashe by the now-shore-raiding entrepreneurs. They still take passengers across in exchange for food, which they try to farm grow on the upper decks (which they covered in dirt).