Looks like a pearly everlasting to me, Anaphalis margaritacea.  We had a patch of them in my coastal mountain home area of Oregon, about 80 miles south of Portland.
 
 Here are more pics to look at and info:
USDA Distribution of pearly everlasting
 
 Some herbal/edibility info on it: 
Pearly Everlasting on EdibleWildFood.com
 
 And some more pics, ID info, and medicinal uses:  
Pearly Everlasting on Montana Plant Life
 
 The flowers are very distinctly ball-shaped, with white bracts and then yellow furry parts inside, as such from Wikipedia:
 
 
 See what you think,
 Kim