RCW 35.13.290: When right-of-way may be included—Use of right-of-way line as corporate boundary.

The boundaries of a city or town arising from an annexation of territory shall not include a portion of the right-of-way of any public street, road, or highway except where the boundary runs from one edge of the right-of-way to the other edge of the right-of-way. However, the right-of-way line of any public street, road, or highway, or any segment thereof, may be used to define a part of a corporate boundary in an annexation proceeding.