Has anyone ever heard of this place? Admittedly, I live on the East Coast, so I know nothing about California geography, but mapping the area suggests that the post office is in the middle of a State Forest and by the looks of the photograph it is in a rather desolate area backed by a rather intimidating mountain or hillside.

Anyway, a quick Google search suggests that:
Quote:
The 2012 Big Bar (zip 96010), CA, population is 134. There are 2 people per square mile (population density).
And this remote area supports a post office that is open five days a week (according to the USPS website).
While it may not be the smallest post office in the US, I would think it certainly has to be in the top 20.