Washington Revised Code Title 36. Counties § 36.32.135. Official seal

The county commissioners of each county shall have and use a seal for the purpose of sealing their proceedings, and copies of the same when signed and sealed by the said county commissioners, and attested by their clerk, shall be admitted as evidence of such proceedings in the trial of any cause in any court in this state; and until such seal shall be provided, the private seal of the chair of such board of county commissioners shall be adopted as a seal.