Went out to the site today to take some pix, and sadly, it seems obvious as to what happened. No skit marks, and no damage to the grass on either side of the road. I believe he lost control after cresting a small hill/bridge, maybe after catching some air over it. The road itself may be straight, but is made of all different types of pavements, isn't too wide, and has quite a shoulder in some spots, so it's easy to want to drive closer to the center (which can give a false sense of security). I wouldn't feel safe at over 70 mph on it, and if there was any traffic at all, it'd probably be best to be under 50 mph.
This is a pic of the small hill/bridge that caused the accident (along with a high-rate of speed), if you look closely you can see the tree as well (middle of the pic, and on the Left). Notice the difference in pavement just at the beginning of the hill/bridge.
