RCW 27.12.110 Intercounty rural library districts — Expansion of existing districts.An existing rural county library district may be expanded into an intercounty rural library district or an established intercounty rural library district may be expanded to include additional counties by joint action of all counties included in the proposed expanded district taken in the same manner as prescribed for the initiation of an intercounty rural library district.
http://apps.leg.wa.gov/rcw/default.aspx?cite=27.12.110
