Click the image for a larger one. We don't know where this is from, but speculation is that it's from some pulp novel centered around the U.S. Camel Corps.

Roughly, it went like this: in 1852 Mississippi senator Jefferson Davis sent a couple of herds of camels from Egypt to Camp Verde just outside San Antonio, Texas, figuring they'd make superior pack animals out in the dusty plains. This lasted for about 10 years before the smell, ill demeanor, and general camel-ness of the animals took their toll on the soldiers' patience, a patience already somewhat taxed by the impending Civil War. Kicked to the curb, a lot of the camels got shuttled off to zoos, circuses, hungry / lonely Scottish immigrants, and so on, but quite a few just ended up wandering around aimlessly out in the dessert, much like hippies, ZZ Top, and eventual victims of Leatherface would some 100 years later.

Anyway, the fez hats and red injuns shitting themselves are probably more like artistic license than fact.

Image thanks to weasel