Wash. Rev. Code § 36.69.020
The formation of a park and recreation district shall be initiated by a petition designating the boundaries thereof by metes and bounds, or by describing the land to be included therein by townships, ranges and legal subdivisions. Such petition shall set forth the object of the district and state that it will be conducive to the public welfare and convenience, and that it will be a benefit to the area therein. Such petition shall be signed by not less than fifteen percent of the registered voters residing within the area so described. The name of a person who has signed the petition may not be withdrawn from the petition after the petition has been filed.
The petition shall be filed with the auditor of the county within which the proposed district is located, accompanied by an obligation signed by two or more petitioners, agreeing to pay the cost of the publication of the notice provided for in RCW 36.69.040. The county auditor shall, within thirty days from the date of filing the petition, examine the signatures and certify to the sufficiency or insufficiency thereof.
If the petition is found to contain a sufficient number of signatures of qualified persons, the auditor shall transmit it, together with a certificate of sufficiency attached thereto, to the county legislative authority, which shall by resolution entered upon its minutes receive it and fix a day and hour when the legislative authority will publicly hear the petition, as provided in RCW 36.69.040.
RCW 36.69.020