Wash. Rev. Code § 7.28.050
That all actions brought for the recovery of any lands, tenements or hereditaments of which any person may be possessed by actual, open and notorious possession for seven successive years, having a connected title in law or equity deducible of record from this state or the United States, or from any public officer, or other person authorized by the laws of this state to sell such land for the nonpayment of taxes, or from any sheriff, marshal or other person authorized to sell such land on execution or under any order, judgment or decree of any court of record, shall be brought within seven years next after possession being taken as aforesaid, but when the possessor shall acquire title after taking such possession, the limitation shall begin to run from the time of acquiring title.
RCW 7.28.050