Here are the legal citations:
Code of Federal Regulations, 36 CFR 261.9: "The following are prohibited:
(g) digging in, excavating, disturbing, injuring, destroying, or in any way
damaging any prehistoric, historic, or archaeological resources, structure,
site, artifact, or property; (h) removing any prehistoric, historic, or
archaeological resources, structure, site, artifact, property."
USDA Forest Service Manual Direction: "Metal Detector Use. Metal
detectors may be used on public lands in areas that do not contain or would
not reasonably be expected to contain archaeological or historical
resources. They must be used, however, for lawful purposes. Any act with
a metal detector that violates the proscriptions of the Archaeological
Resources Protection Act (ARPA) or any other law is prosecutable. Normally,
developed campgrounds, swimming beaches, and other developed recreation
sites are open to metal detecting unless there are heritage resources
present. In such cases, Forest Supervisors are authorized to close these
sites by posting notices in such sites."
ARPA, 16 U.S.C. 470cc: "No person may excavate, remove, damage, or
otherwise alter or deface or attempt to excavate, remove, damage or
otherwise alter or deface any archaeological resources located on public
lands or Indian lands unless such activity is pursuant to a permit..."
Definitions: Archaeological resource means any material remains of
prehistoric, or historic human life or activities which are of
archaeological interest and are at least 50 years of age, and the physical
site, location, or context in which they are found. Prehistoric resource
means any structural, architectural, archaeological, artifactual or other
natural remains of past human life or activity generally prior to the
advent of written records and of anthropological interest, and the physical
site, location, or context in which they are found.
PLEASE NOTE, THIS IS IN MS!! Should be National though.