2015 District of Columbia Code
Division I - Government of District.
Title 10 - Parks, Public Buildings, Grounds, and Space.
Subtitle II - Public Buildings and Grounds.
Chapter 5 - Regulatory Provisions.
Subchapter VI - Capitol Grounds and Botanic Garden Tunnel.
§ 10-511.03. Tunnel under Capitol Grounds and Botanic Garden grounds -- Right, title and interest to remain in the United States; jurisdiction and responsibility of Mayor.

Except as provided in § 10-511.06, nothing in this subchapter shall be construed to grant to the Mayor of the District of Columbia any right, title, or interest in or to any real property of the United States, and reservation 12 shall in its entirety continue to be a part of the United States Capitol Grounds, and square W-576 shall in its entirety continue to be a part of the United States Botanic Garden grounds. The Mayor shall have jurisdiction and control of, and sole responsibility for the operation and maintenance of, those portions of the tunnel beneath square W-576 and reservation 12.