Signed by President Lyndon B. Johnson on Sept. 3, 1964.

Restricts grazing, mining, timber cutting and mechanized vehicles in areas designated by Congress as "wilderness" to "assure that an increasing population . . . does not occupy and modify all areas within the United States and its possessions, leaving no lands designated for preservation and protection in their natural condition."

Currently, approximately 106 million acres are designated as wilderness in the United States.