An island or accumulation of land formed in a stream which is not navigable belongs to the owner of the shore on that side where the island or accumulation is formed, or if not formed on one side only, to the owners of the shore on the two sides, divided by an imaginary line drawn through the middle of the river.
N.D. Cent. Code § 47-06-09
Islands and relicted land in non-navigable streams
Official source: North Dakota Legislative Branch. Reproduced from public-domain North Dakota statutes; confirm against the official source for the current text. Not legal advice.