According to my Hammond World Atlas, this county has a very small population and the county seat’s population is smaller still–only 5 people. How can a county with such a small population survive? 
According to wikipedia, it has over 7000 people, which isn’t that small, and a population density of 38 people/square mile, which isn’t really that sparse at all. Even California has two counties (Alpine and Sierra) that are smaller and less dense.
According to the wiki article, it has some plantations that date back to the original Virginia Colony, so those are probably large, fairly sparsely populated tracts that are worth some serious coin and ergo tax revenue.