RCW 27.12.010(3): "… a municipal corporation organized to provide library service for all areas outside of incorporated cities and towns on a single island only, and not all of the area of the county, in counties composed entirely of islands and having a population of less than twenty-five thousand at the time the island library district was created: PROVIDED, That any city or town meeting the population requirements of RCW 27.12.360 may be included therein as provided in RCW 27.12.360 through 27.12.390" (i.e., RCW 27.12.370, RCW 27.12.380, and RCW 27.12.390)
"It is hereby declared to be the policy of the state, as part of its provision for public education, to promote the establishment and development of public library service throughout its various subdivisions." RCW 27.12.020
The legal authority and the process for establishing libraries are described in the Revised Code of Washington:
"Any governmental unit has power to establish and maintain a library, either by itself or in cooperation with one or more other governmental units." RCW 27.12.025
"A library may be established in any county, city, or town either (1) by its legislative body of its own initiative; or (2) upon the petition of one hundred taxpayers of such a governmental unit, the legislative body shall submit to a vote of the qualified electors thereof, at the next municipal or special election held therein (in the case of a city or town) or the next general election or special election held therein (in the case a of a county), the question whether a library shall be established; and if a majority of the electors voting on the question vote in favor of the establishment of a library, the legislative body shall forthwith establish one." RCW 27.12.030
In addition, RCW 27.12.360 - RCW 27.12.400 provide the process that enables a city or town to annex with a district for library services.
The tax-supported public library is a legal entity guided by a board of trustees whose powers and duties are described Library Trustees - Overview. All trustees are obliged to read and understand the federal, state, and local laws and regulations that govern their library as well as the more general laws that apply. Board members should thoroughly understand the extent of their legal authority and responsibilities.
According to the Municipal Services and Research Center (MSRC) attorney nothing in RCW 27.12.470 authorizes the consolidation of a rural partial library district with any other district or type of public library unless the boards of all the library district involved approve the consolidation. The last paragraph of RCW 27.12.470 was cited to support this claim. The MSRC attorney further stated that there no other requirements such as a vote of the people required by the statute.