Winter Wren

Winter/Pacific Wren complex, both species are uncommon in the mapped location. The two species are so similar, they were considered conspecific until recently. I believe Pacific are more rufous in coloration than Winter, but considering both are equally uncommon in your area, it'd be tough to tell here.
I am leaning towards Winter Wren (Troglodytes hiemalis), though, based on the more patterned side. I suggest reporting this to eBird: http://ebird.org/content/ebird/