If a rural partial-county library district annexes a city or town that maintains its own library, which municipal corporation owns the property of the already established library?

An informal AGO Opinion issued 12/15/1994, signed by Assistant Attorney General Jean M. Wilkinson and addressed to Mary Y. Moore, states:

“Because neither RCW 27.12.470 (relating to rural partial-county libraries) nor RCW 27.12.355 – .395 (relating to annexation by rural county libraries) state that the municipal library assets transfer to the annexing rural county or partial-county library district, the common law rule… dictates that the annexation does not trigger a change in ownership of municipal library assets.”