43 C.F.R. § 3503.32
You may describe acquired lands by metes and bounds, or you may also use the description shown on the deed or other document that conveyed title to the United States. If you are applying for less than the entire tract acquired by the United States, describe the land using courses and distances tied to a point on the boundary of the requested tract. Where the acquiring agency assigned a tract number to the identical tract you wish to permit or lease, you may describe those lands by the tract number and include a map which clearly shows the lands with respect to the administrative unit or the project of which they are a part. In States outside of the public land survey system, you should describe the lands by tract number, and include a map.
43 C.F.R. §3503.32