RCW 11.98.140

If, during the one hundred fifty years following the effective date of an instrument creating a trust, any of the trust assets should by the terms of the instrument or pursuant to any further trust or other disposition resulting from exercise of the power of appointment granted in or created through authority under such instrument, become distributable or any beneficial interest in any of the trust assets should by the terms of the instrument, or such further trust or other disposition become vested, such assets shall be distributed and such beneficial interest shall validly vest in accordance with the instrument, or such further trust or other disposition.