This is a shot of the red clay found around the Roanoke area. It’s an acidic soil that’s common around the southeastern United States; sciencey types call it a “ultisol.” The rust color results from … actual rust, if I understand correctly. It’s full of iron oxide.
I don’t think my camera phone does it justice — it’s actually redder than it appears below. I have no doubt Roanoke natives hardly notice it, but it looks strange at first to a carpetbagger.