What: Welcome to Sunny California
Why: It is an image that, to me, recalls a sort of dustbowl era California akin to something from the pages of Steinbeck. It shows the gateway to what was a promised land for many midwesterners who could no longer till the parched soil in the years of the Great Depression. And it's in color, adding even more of a sense of wonder compared to the typically austere monochrome depictions of the tough years of the 1930's. The auto at left adds a particular sense of era context to this interesting scene.
When: There is one significant clue that seems to offer a date to this image. A snippet of a license plate can be seen in the lower right corner, that, provided it is a California tag, dates this image to being in either late 1939 or early 1940, which tends to be consistent with some of the other elements such as signage and the like.
Where: Winterhaven, CA. I initially looked at this and thought it might be along the historic Route 66 corridor, but looking at scenes and street views along the border, it didn't seem to be. Fortunately, this image came along with a companion taken on the other side of the border, which shows signage for Yuma, AZ, and some inspection along the border near Yuma revealed an interesting surprise, namely, that this old inspection station was still there, although quite decrepit. There have been a few items written about the old station, at least one of which misinterprets it as being an old railroad station, which it doesn't seem to have been.
Who: No actual inspectors to be seen here.