Wash. Rev. Code § 11.104B.020
(1) Except as otherwise provided in the terms of a trust or this chapter, this chapter applies when this state is the principal place of administration of a trust or estate, subject to the following rules:
(2) Without precluding other means to establish a sufficient connection with the designated jurisdiction in a directed trust, terms of the trust which designate the principal place of administration of the trust are valid and controlling if:
[ 2021 c 140 s 2104.]