Roughly (I am no historian), during WWII, the US government didn't know how far he could trust its Japanese-American citizens (the "nisei") who were numerous in the western states. So, by fear that they could spy for the Japan Empire or whatever, they were regrouped and "relocated" in camps like Manzanar, situated far from the main cities, I think.
I was hoping that, recognizing japanese, an american vehicle of the 1940's and a not very japanese landscape, puzzlers could be led to the picture and the solution. It appears that Joao knew were to look.