Wash. Rev. Code § 38.32.030
No person belonging to the military forces of this state shall be arrested on any warrant, except for treason or felony, while going to, remaining at, or returning from any place at which he or she may be required to attend military duty. Any members of the organized militia parading, or performing any duty according to the law shall have the right-of-way in any street or highway through which they may pass and while on field duty shall have the right to enter upon, cross, or occupy any uninclosed [unenclosed] lands, or any inclosed [enclosed] lands where no damage will be caused thereby: PROVIDED, That the carriage of the United States mail and legitimate functions of the police and fire departments shall not be interfered with thereby.
RCW 38.32.030