There is a Youtube video about how to build a DTV UHF antenna from wire coathangars and a strip of moulding. A fella I work with did it and liked the result. We both live in the Seattle area as well. He is in Auburn / Federal Way area.
http://www.youtube.com/watch?v=EWQhlmJTMzw
The video is entertaining too. In case the link does not work search on "coat hanger DTV antenna".