Archaeologists study the past from artifacts. However, information comes not from the artifacts alone, but from the context in which they are found. The association of an artifact with other stone tools and food remains, its depth below the surface, and the type and color of the soil surrounding it are some of the things archaeologists need to know.
Why you should not dig for artifacts
An artifact out of context gives only a part of the information needed. This is the reason that archaeologists ask people to refrain from digging for artifacts.
Most people do not realize that they are contributing to the destruction of archaeological sites when they dig to "see what is there" in caves or elsewhere. These are non-renewable resources; once destroyed, they are gone forever.
Other kinds of destruction
Everyone's basic heritage--our knowledge of the past--is also being destroyed by farming, the expansion of cities and suburbs (caused by continuous population growth), digging foundations for buildings, road and bridge building, putting in parking lots, and any other activity which disturbs the ground and the artifacts which lie within it.
How you can help
If you surface-collect artifacts, keep them separated by site. These archaeological sites can then be registered with the Missouri State Historic Preservation Office (SHPO). Site locations are confidential. SHPO will send you the site number to keep with the artifacts, or better yet, the artifacts can be labeled with the site number. These will still be your artifacts, but you will have done what is ethical and responsible to contribute to the archaeological record of Missouri.