Springtime for southern Arizona archaeology means… the Brigadoon Effect! Now you see it, now you don’t.
As many of you probably know, vegetation can be an archaeologist’s friend or foe. Trees and creosotes can hide site features—or they can reveal them as if by magic. Archaeologists call this seasonal aid “The Brigadoon Effect,” after Brigadoon, a 1954 musical about an enchanted Scottish village that appeared only a few times each century.
In March, a team of Arizona Site Stewards who have been working with Archaeology Southwest to document sites in Pinal County returned to a Hohokam village site near the Picacho Mountains to see what the spring vegetation might reveal. Two years ago, we had found the habitation site based on the presence of a cluster of trash piles, but we found no evidence of houses, such as embedded stones.
What a difference a little rain makes! When we visited, the plant “matting” covered the desert floor, but the plants did not grow as thickly along the adobe walls. The plant coverage was only 50–70% as thick on the walls. Although rooms were not always as apparent as in the picture, we were able to locate and map about twenty rooms in the area. At McClelland Platform Mound, we saw a similar effect that revealed much thicker walls on top of the mound and in the immediate area.
So, next spring, while it lasts, be sure to keep your eyes open for some “enchanting” views of archaeological sites.
