RCW 84.36.230: Interstate bridges—Reciprocity.

Any bridge, including its approaches, over rivers or bodies of water forming interstate boundaries, which bridge has been constructed or acquired and is being operated by any foreign state bordering upon such common interstate boundary, or which has been constructed or acquired and is being operated by any county, city or other municipality of such foreign state, shall be exempt from all property and other taxes in the state of Washington, if the foreign state exempts from all taxation any bridge or bridges constructed or acquired and being operated by the state of Washington or any county, city or other municipality thereof.