For a complete list of US Cultural Protection Legislation check out http://archnet.uconn.edu/topical/crm/crmusdoc.html
There are many laws, both federal and state, which serve to protect archaeological sites and artifacts from being destroyed and stolen.
As an example of one of these many laws, below is an excerpt from the Archaeological Resources Protection Act of 1979.
Sec. 6. (a) No person may excavate, remove, damage, or otherwise alter or deface any archaeological resource located on public lands or Indian lands unless such activity is pursuant to a permit issued under section 4....
(b)No person may sell, purchase, exchange, transport, receive, or offer to sell, purchase, or exchange any archaeological resource if such resource was excavated or removed from public lands or Indian lands...
(c) No person may sell, purchase, exchange, transport, receive, or offer to sell, purchase, or exchange, in interstate or foreign commerce, any archaeological resource excavated, removed, sold, purchased, exchanged, transported, or received in violation of any provision, rule, regulation, ordinance, or permit in effect under State or local law.
(d) Any person who knowingly violates, or counsels, procures, solicits, or employs any other person to violate, any prohibition contained in subsection (a), (b), or (c) of this section shall, upon conviction, be fined not more than $10,000 or imprisoned not more than one year, or both: Provided, however, That if the commercial or archaeological value of the archaeological resources involved and the cost of restoration and repair of such resources exceeds the sum of $5,000, such person shall be fined not more than $20,000 or imprisoned not more than two years, or both. In the case of a second or subsequent such violation upon conviction such person shall be fined not more than $100,000, or imprisoned not more than five years, or both.
(e) The prohibitions contained in this section shall take effect on the date of the enactment of this Act.
(f) Nothing in subsection (b)(1) of this section shall be deemed applicable to any person with respect to an archaeological resource which was in the lawful possession of such person prior to the date of the enactment of this Act.
(g) Nothing in subsection (d) of this section shell be deemed applicable to any person with respect to the removal of arrowheads located on the surface of the ground.
Read the full text of the Archaeological Resources Protection Act
April M. Beisaw