I don't know about all areas in Washington, but I have seen Ospreys carrying nesting materials over a week ago in the Salmon Creek area of Vancouver, WA (Clark County). This was over a week ago. This is not exactly the behavior of birds that are just passing through.
Michelle MaaniVancouver, WA
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <
http://mailman11.u.washington.edu/pipermail/tweeters/attachments/20180402/a88efa20/attachment.html>