Back in the 1880', Snoqualmie had the biggest hop production fields in the US. Then the downy mildew hit, and the crops died. They moved to the east side of the Mts. and the rest is history as far as Yakima goes.
Cascade absolutely thrives here. Willamette, too. Not sure about Chinook or Columbus, but Centennial does really well, so I think that those two should as well. You really have to be very careful about mildew. I don't know how to control it for hops (though there are plenty of anti-fungals that work great for non-food plants).
I'd send Ralph Olson a note and ask him what he thinks about as far as that goes (as well as that chick from Colorado -- can't remember her name off the top of my head but man, she really knows her stuff).
hops@hopunion.comHTH-