 All of the federally owned lands, except for North Breton Island, in Breton NWR became part of the National Wilderness Preservation System on January 3, 1975 (Public Law 93-632).North Breton was excluded because an oil facility, owned by Kerr-McGee, Inc., was located on that island.The Breton Wilderness, according to the Clean Air Act, is listed as a Class I Prevention of Significant Deterioration Area.