Thanks to Dan Harrison of Henry Ford Community College for these links.
National Archaeological Database (NADB) - reports, maps, permits
NADB-Reports is an expanded bibliographic inventory of over 350,000 reports on archaeological investigation and planning, mostly of limited circulation. This "gray literature" represents a large portion of the primary information available on archaeological sites in the U.S. This internationally recognized resource is maintained through a cooperative agreement between the National Park Service (NPS) and the Center for Advanced Spatial Technologies (CAST) at the University of Arkansas.