Metal detecting laws vary from state to state, but some federal laws are also in place to govern treasure hunting. In Minnesota, metal detecting in state parks is strictly prohibited, but there are no laws that state that it is illegal on federal grounds. However, there are laws in place to protect artifacts discovered on federal grounds. All metal detector hobbyists are responsible for understanding these laws, so it is important to check the laws for whatever state you are in so that none of these laws are broken.
In some states, metal detecting laws are fairly ambiguous because they do not prohibit metal detecting; rather, they usually refer to the artifacts found when metal detecting. This is not the case in Minnesota, where metal detecting laws are clearly stated. According to the Minnesota Office of the Revisor of Statutes, Minnesota has administered rules for environmental protection. These rules specifically state that the use of metal detectors in state parks is not permitted with exception of special circumstances where a special permit has been obtained for scientific research and with a field archeology license that has been issued by the state archaeologist.
The Archaeological Resources Preservation Act (ARPA)
The Archaeological Resources Preservation Act (ARPA) became a law on October 31, 1979. Although this federal historic preservation law does not explicitly forbid metal detecting, it is important to understand the law protecting any artifacts that might be discovered before doing any metal detecting or removing treasures found. The basic idea of the ARPA is that it forbids any resources found on public grounds or Indian grounds from being dug up, removed or modified without the issuance of a permit beforehand.
National Historic Preservation Act (NHPA)
The National Historic Preservation Act (NHPA) was passed in 1966 and is another federal law in addition to the ARPA. The NHPA appointed Congress as not only a partner but also a leader in historic preservation. The NHPA assigns the government several responsibilities. One responsibility is to provide guidance for preservation. Under the NHPA, the government is also to partake in public support for preservation as well as increase public support of preservation. A third government responsibility is to make it possible for modern society to coexist with historic and prehistoric resources. Like the ARPA, the NHPA does not prohibit the act of metal detecting but that it is illegal to remove artifacts without a permit. The NHPA explains that no artifacts thought to be 100 years of age or older should be disturbed.
Private Property Laws
It is also important to follow private property laws when metal detecting. Metal detecting on private property without receiving permission first is considered trespassing; therefore, one should obtain permission before metal detecting on private property. Secondly, any object found on private property remains the property of the owner of that land; removing any such object from private property is considered theft and is illegal. Nothing should be removed from private property without the consent of the property owner.