You need to check out Field and Forest in Harrisville, NH they are not open to the public so it's a little tricky getting in but they do have some open weekends.
https://www.facebook.com/FieldandForestRecreationArea/
My rig is on the heavy side close to 6000lbs normal stuff 60/14 axles sitting on 44's run 150 psi in the lowers and 250-260psi in the uppers with about 6in of chrome showing.