The National Strategy for Federal Archeology, under federal
policy, favors conserving sites in place. Excavation incurs
expense as well as the responsibility for writing archeological
reports and caring for collections. Once a site is stabilized,
it can always be excavated later. Now and in the future,
technology such as ground penetrating radar and remote sensing
will aid in the effort.
Sites are subject to natural and cultural threats, such as erosion and construction projects. Federal agencies and their partners use a host of methods to conserve sites under public stewardship. The National Park Service worked closely with the Corps of Engineers to conserve Puerto Rico's El Morro Castle; the Forest Service erected a museum-research facility over a 9,500-year-old buffalo kill site in Nebraska's Oglala National Grassland.