Section 64.16 - Retention and custodial requirements for records(a) Financial records, supporting documents, statistical records, and other records pertinent to a grant program shall be retained for a period of three years after final payment. The records shall be retained beyond the three-year period if audit findings have not been resolved.(b) The Secretary of the Interior and the Comptroller General of the United States, or any of their duly authorized representatives, shall have access to any books, documents, papers, and records of the State and local governments and their subgrantees which are pertinent to a specific project for the purpose of making audit, examinations, excerpts, and transcripts.