The Secretary of Agriculture in regulating grazing on the national forests and other lands administered by him in connection therewith is authorized, upon such terms and conditions as he may deem proper, to issue permits for the grazing of livestock for periods not exceeding ten years and renewals thereof: Provided, That nothing herein shall be construed as limiting or restricting any right, title, or interest of the United States in any land or resources.
16 U.S.C. § 580l