Removing material from archaeological sites on private land with the permission of the landowner is legal. However, when the material is taken from federal public lands, then the activity becomes illegal. Archaeological sites on federal public lands and the heritage values they contain are part of our national heritage. It is our collective responsibility to protect this heritage, whether it be Native American sites, Russian-American sites, or historic mining sites. Archaeology is the study of past human cultures.
Excavation is one of the archaeologist's fundamental means of learning about the past.
This is actually more complicated than it sounds. Archaeological field methods are complex, and a considerable amount of training and supervision is necessary before excavation can be carried out effectively. It is important that the untrained person not attempt to perform his or her own excavation. Even archaeologists cannot excavate at will on federal lands. They must obtain a permit and conduct work in accordance with the law.