We're not archaeologists or scientists or anything like that, but we're curious as heck. One thing we constantly ask ourselves is, "When are we going to eat? The other thing we constantly ask ourselves is, "How old is this place?"

The process is fairly simple. You look for man-made stuff. You find man-made stuff. You determine when the stuff was made. The oldest stuff you find should indicate the age of the site.

For instance, you find a 1968 quarter and a 1910 quarter. You can pretty much bet that the site dates at least from the beginning of the twentieth century. It could be older, of course, since that 1910 quarter could have been old when it was lost. And, some contemporary explorer could have brought his 1910 coin collection with him yesterday and lost it. But it's a safe assumption that the site is at least as old as the artifact.

Now, your chances of finding things with dates stamped on them are sparse, so you have to do a little detective work.

Look around you. Are there cans? What kind of cans are they? Certain cans were manufactured at different times. Did they use plywood? Plywood wasn't commercially available in the middle of the 1800's, so you know what you're looking at came after that. Welds? Concrete? Same thing. Below is a small list of when certain things came into general use, which should help you date what you're looking at.

LATE     discovery         1900-1907
         prosperity        1908-1918
         decline           1919
         partial recovery  1924
         war increases     1939
         post-war relative
         prosperity        1946-1954

Source- An Outline of the Mining History of the State of Nevada, 1924, F.C. Lincoln, Outline of Nevada Mining History, Nevada Bureau of Mines and Geology, 1993.

Patented - 1865
Commercially available -1905
Begins widespread use - 1930
Use in home manufacturing- 1940
Source - APA-The Engineered Wood Association

1st structures built - 5600 BC
Concrete blocks manufactured - 1868
1st reinforced concrete bridge - 1889
Cement tests standardized - 1900
1st concrete homes in US - 1908
Source - Dee Concrete Accessories