36 C.F.R. § 51.70
In the event a concessioner under a 1965 Act concession contract is awarded a new concession contract replacing a possessory interest concession contract, the concessioner will obtain a leasehold surrender interest in its existing possessory interest real property improvements under the terms of the new concession contract. The concessioner will carry over as the initial value of such leasehold surrender interest (instead of initial construction cost) an amount equal to the value of its possessory interest in real property improvements as of the expiration or other termination of its possessory interest contract. This leasehold surrender interest will apply to the concessioner's possessory interest in real property improvements even if the real property improvements are not capital improvements as defined in this part. In the event that the concessioner had a possessory interest in only a portion of a structure, depreciation for purposes of leasehold surrender interest value under the new concession contract will apply only to the portion of the structure to which the possessory interest applied. The concessioner and the Director will seek to agree on an allocation of the leasehold surrender interest value on a unit by unit basis.
36 C.F.R. § 51.70