Government documents are in the public domain, and have no copyright
restrictions. If a private contractor produced the map for the government,
they may have a copyright on it, but you would see their name on the map
somewhere. Hope this helps.

Andrew Nitz
Cataloger
Bibliographic Systems Branch
Sales Management Division
Superintendent of Documents
United States Government Printing Office
710 North Capitol Street, NW
Washington DC 20401
202-512-1705
202-512-1655 (fax)