Wash. Rev. Code § 29A.04.210
Except for service and overseas voters, only persons registered to vote shall be permitted to vote:
[ 2009 c 369 s 4; 2003 c 111 s 133; 1965 c 9 s 29.04.010. Prior: 1955 c 181 s 8; prior: (i) 1933 c 1 s 22, part; RRS s 5114-22, part. (ii) 1933 c 1 s 23; RRS s 5114-23. See also 1935 c 26 s 3; RRS s 5189. Formerly RCW 29.04.010.]
Overseas, service voters, same ballots as registered voters: RCW 29A.40.010.