Federal

http://www.cr.nps.gov/laws.htm
This National Park Service web page provides links to federal laws, regulations, standards and guidelines, and executive orders.

http://www.cr.nps.gov/history/online_books/fhpl/index.htm
The 2006 edition of Federal Historic Preservation Laws:  The Official Compilation of U.S. Cultural Heritage by the National Park Service is available in .pdf format.