Summary

Determining the age of a refuse dump, railroad logging camp, cabin site, or other potentially historical resource depends in large part on your ability to date the artifacts you find there.  Be aware, though, that many sites saw more than one period of use.  You may find 1860s “black” glass mixed with cone-top beer cans dating to the 1930s, or broken bits of Fiestaware lying side-by-side with a pop-top soda can.  Such admixture could mean that the historical integrity of your site has been compromised.  However, it is typical of archaeological sites in California to have more than one period represented, so mixing does not automatically mean your site lacks significance.  When recording an historical site, it is important to determine as closely as possible the time period(s) represented, and the relative percentages of items from each period.  You can then construct a kind of time-line for the assemblage:

As we have noted, the ultimate goal of archaeology and anthropology is to understand how societies and cultures change over time, by interpreting the artifacts and sites they leave behind.  Clues to human behavior are embedded in material culture (artifacts and features), and the archaeologist’s task is to find these clues and unravel their meanings. 

The age of a site is not the only clue to consider – even sites from the same time period can look completely different.  For example, domestic refuse from a household (decorated dishes, canning-jar inserts, children’s toys, etc.) will look very different from garbage left by a large construction crew (multi-serving food, coffee, and evaporated-milk cans, tobacco pails, undecorated “cafeteria” ware).  Likewise, a small family homestead from the 1850s may be more significant that a mining camp of the same age, because women and children were rather uncommon on the western mining frontier.  Remember, too, that the oldest site is not always the most important one.  A 1940s internment camp from World War II may have much more historical significance than a much older 1890s railroad-logging camp, because of importance of that war to our nation’s history and the effects of those internments on Japanese-American society. 

In summary, archaeologists and historians must consider all aspects of a site:  its age, function, types of artifacts, degree of preservation (integrity), and context within a larger historical framework.