Tweets:
Gyrfalcon still at that location at 4pm Wednesday. Seen before I parked the car!
Introduced myself to the entire family across the street - the Thiele family - who reported it had been there for three days, same tree, but they thought it was a hawk or small eagle. They looked at it through my equipment and I showed them pictures for comparison in all the raptor books I hauled out of my trunk. They were quite interested and even called other neighbors out to show them!
When I mentioned others might be coming to see it, and inquired about parking, they are happy to share this sighting, and welcome you to park on their side of the street, (even on their grass!) as long as the driveway isn't blocked.

Thanks to Houston, et.al, for the info on location....
NW corner of 244th Ave SE and SE 436th St in Enumclaw, King County
~Donna Poppe