Wash. Rev. Code § 35.13.340
The boundaries of a city shall be adjusted to include or exclude the remaining portion of a parcel of land located partially within and partially without *of the boundaries of that city upon the governing body of the city adopting a resolution approving such an adjustment that was requested in a petition signed by the owner of the parcel. A boundary adjustment made pursuant to this section shall not be subject to potential review by the boundary review board of the county within which the parcel is located if the remaining portion of the parcel to be included or excluded from the city is located in the unincorporated area of the county and the adjustment is approved by resolution of the county legislative authority or in writing by a county official or employee of the county who is designated by ordinance of the county to make such approvals.
Where part of a single parcel of land is located within the boundaries of one city, and the remainder of the parcel is located within the boundaries of a second city that is located immediately adjacent to the first city, the boundaries of the two cities may be adjusted so that all of the parcel is located within either of the cities, if the adjustment was requested in a petition signed by the property owner and is approved by both cities. Approval by a city may be through either resolution of its city council, or in writing by an official or employee of the city who has been designated by ordinance of the city to make such approvals. Such an adjustment is not subject to potential review by the boundary review board of the county in which the parcel is located.
Whenever a portion of a public right-of-way is located on such a parcel, the boundary adjustment shall be made in such a manner as to include all or none of that portion of the public right-of-way within the boundaries of the city.
As used in this section, "city" shall include any city or town, including a code city.
RCW 35.13.340
*Reviser's note: The word "of" appears to be unnecessary.