Unsecure image, only https images allowed: http://img191.imageshack.us/img191/8513/20feet.png Not sure about 20 down, but it looks pretty far.
It might be the angle, of course.
That's the smaller of the two, which is more like 10-12 feet. I measured the bigger one at 19x28 feet to the edge of the road so I just rounded up to 20x30 because it's close enough and if you are landing at 19x28, you are casing hard