Wash. Rev. Code § 36.34.160
When, in the judgment of the board of county commissioners, it is found desirable to lease the land applied for, it shall first give notice of its intention to make such lease by publishing a notice in a legal newspaper at least once a week for the term of three weeks, and shall also post a notice of such intention in a conspicuous place in the courthouse for the same length of time. The notice so published and posted shall designate and describe the property which is proposed to be leased, together with the improvements thereon and appurtenances thereto, and shall contain a notice that the board of county commissioners will meet at the county courthouse on a day and at an hour designated in the notice, for the purpose of leasing the property which day and hour shall be at a time not more than a week after the expiration of the time required for the publication of the notice.
RCW 36.34.160