I take that back, it does look like the sun did it. Either the sun did it or its a cloud reflection. The thing that threw me off is that there is a split in the photo and the white area ends abrubtly where the split is. But probably what happened is they shot the area below the split either on a different day, or on a different pass of the plane when the conditions were slightly different.
Bob,
the sandy area which Steve identified as a gun club/shooting range is that sandy area I was refering to on our trip this past Saturday. Now that Steve mentions it, I do recall coming across a gun range back in there at one time. There was a gate across the road and signs posted. It makes sense.