41 C.F.R. § 102-75.485
In such a case, DOI must notify the appropriate GSA Public Buildings Service (PBS) Regional Office immediately by letter when title to the historic property is to be revested in the United States for noncompliance with the terms and conditions of disposal or for other cause. The notification must cite the legal and administrative actions that DOI must take to obtain full title and possession of the property. In addition, it must include an adequate description of the property, including any improvements constructed since the original conveyance to the grantee. After receiving a statement from DOI that title to the property is proposed for revesting, GSA will review the statement and determine if title should be revested. If GSA, in consultation with DOI, determines that the property should be revested, DOI must submit a Report of Excess Real Property, Standard Form 118 to GSA. GSA will review and act upon the Standard Form 118, if acceptable. However, the grantee must provide protection and maintenance of the property until the title reverts to the Federal Government, including the period of the notice of intent to revert. Such protection and maintenance must, at a minimum, conform to the standards prescribed in the GSA Customer Guide to Real Property Disposal.
41 C.F.R. § 102-75.485