36 CFR § 254.42 - Valuation of tracts.
(a) Approximately equal value shall be determined by comparing and evaluating the elements of value on the lands or interest in lands to be interchanged. Elements of value to be considered include size, shape, location, physical attributes, functional utility, proximity of other similar sites, and amenities in the immediate environs of the parcel. Findings that tracts are approximately equal in value shall be documented. An applicant must signify acceptance of the value determination by signing the documented findings prior to the interchange.
(b) Equal value in sale or exchange transactions shall be developed by recognized appraisal methods following Forest Service appraisal procedures and the Uniform Appraisal Standards for Federal Land Acquisition. The date of the value estimate will be current with the date of sale or exchange.