When I was living in WA, I used to drink lots of Black Butte Porter from
Deschutes Brewery in Bend, Or.
Rogue's Shakespeare Stout and Mocha Porter are pretty good too. They are also out of Oregon.
New Belgium Brewery in Colorado makes a good abbey ale as I recall and is available in your area. If you're in Seattle, the
brewery at Pikes Place has some good dark beers too.