When an area is subdivided and a plat of the subdivision is approved, filed, and recorded, all streets, alleys, thoroughfares, parks and other public areas shown on the plat are considered to be dedicated to public use.
AS 40.15.030
Dedication of streets, alleys, and thoroughfares
Official source: Alaska State Legislature. Reproduced from public-domain Alaska statutes; confirm against the official source for the current text. Not legal advice.