23 Del. C. § 1506: Filing federal maps and reports.

The Secretary of State shall procure duplicate copies of the federal government’s manuscript map or maps, report or reports accompanying the same, from time to time, and file 1 of the copies in the Secretary’s office at Dover and the other in the office of the Recorder of Deeds for New Castle County. The copies when so filed, or certified copies thereof, shall be competent evidence for all purposes.