Montana counts until the flatlands. :-)
I spent a lot of my teen years devouring Richard Brautigan. I liked his perspective and it was inspiring to think that he had traveled many of the same areas I had. Some of the short short stories were written in places I had been or would later visit.
The Northwest in general has a growing number of incredible writers, and a history filled with many forgotten or ignored. As an Idahoan, Vardis Fisher comes to mind.