The national recreation area shall comprise all of the Grand Island in Lake Superior, Michigan, and all associated rocks, pinnacles, and islands and islets within one-quarter mile of the shore of Grand Island. The boundaries of the Hiawatha National Forest are hereby extended to include all of the lands within the national recreation area. All such extended boundaries shall be deemed boundaries in existence as of , for the purposes of sections 100506(c) and 200306 of title 54. All federally owned lands within the national recreation area on , are hereby components of the National Forest System and shall be administered by the Secretary of Agriculture as provided in this subchapter.