RCW 27.12.010 (8): "… a municipal corporation organized to provide library service for a portion of the unincorporated area of a county. Any city or town located in the same county as a rural partial-county library district may annex to the district if the city or town has a population of one hundred thousand or less at the time of annexation."
May be created in a portion of the unincorporated area of a county if a rural county library district, intercounty rural library district, or island library district has not already been created in the county.
See also RCW 27.12.470.
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.
May annex any city or town with a population of 100,000 or less at the time of annexation (RCW 27.12.010(8)) and adjacent unincorporated territory in the county.
See also RCW 27.12.470.
By vote of registered voters within the governmental unit in which the library is located as prescribed in RCW 27.12.030.
See also RCW 27.12.320.