Mike, I did a quick check at the Cornell CBC site :
http://www.audubon.org/bird/cbc/hr/
and found that there was only one Caspian Tern seen in Washington and Oregon
from count 97-present (at least one that was officially registered with CBC
officials). There was one bird counted during the 98th season at Everett.

Jason Paulios
Jpaulios at earthlink.net
Olympia, WA