Hi,
There is a fairly good summary of Broad-wing sightings in WA in the recent Birds of Washington by Terry Wahl, Bill Tweit and Steve Mlodinow (page 117).
Kent Woodruff and the crew at Chelan Ridge were and are the first and the only ones to report Broad-wings on a regular basis during fall migration in WA. Despite the earlier Tweeters comment, we did not have any Broad-wing sightings at Entiat Ridge over a seven year period. They were never regular there. Nor are they regular, in my experience, in western WA. In fact, I have never seen one here and envy people like Charlie that have.
As a breeding bird, they extend westward in a narrow band across North America into Alberta with small clusters reported in BC (Wheeler 2003). We always speculated that these birds were likely the ones seen at Chelan Ridge in fall.
Wayne's comments about birds being seen at Prince Rupert was news to me. Remarkable. If they are expanding in number there, perhaps we are looking at increasing sightings here in w. WA.
But I would also agree with Wayne that all such sightings should be documented with photos if possible. Experience has shown how difficult it can be to correctly identify hawks.

Bud Anderson
Falcon Research Group
Box 248
Bow, WA 98232 USA
(360) 757-1911 (office)
(206) 962-7838 (cell)
bud at frg.org