You will have to ask yourself this question, can your grandma's Buick make it up the hill without acting in an erosive manner?
If she spins a tire climbing to the top, or any given CO (Conservation Officer) thinks she might, you cannot legally be there, unless however, it is signed as an ORV route. Which, the hill you are reffering to is not.
Also, you must obtain a camping permit for dispersed camping on State Land and I would also look into camping on the NG base as it may be closed to overnight stays. Camping permits for state land can be picked up at any DNR office between the hours of 9am an 5pm.