Authorizes the Secretary of the Interior to convey islands and other public lands omitted from prior surveys to States or their political subdivisions. Prohibits such conveyance unless the applicant prepares, and the Secretary approves, a comprehensive land-use plan covering the lands involved. Directs the Secretary to charge the fair market value of such lands, unless he determines that it is in the public interest not to do so. Provides for an automatic reversion to the United States of those conveyed lands which are not used in accordance with the plan required by this Act.