43 CFR 47.40: How must properties be described?

The description of properties involved in a land exchange must be either:

(a) Based upon a survey completed in accordance with the Public Land Survey System laws and standards of the United States; or

(b) If Public Land Survey System laws and standards cannot be applied, based upon a survey that both:

(1) Uses other means prescribed or allowed by applicable law; and

(2) Clearly describes the property and allows it to be easily located.