To me its not the 4$ or 10$ but in how the money will be used. Yes sites do need to be maintained but the real problem is enforcement of existing regulations. Many times have I seen people using the sites without permits. If I thought the generated funds would be used for enforcement then I might be more in favor. Our powers that be though have a way of diverting and watering down funds like these to the point that I wander if they would have any impact. Maybe everyone who enters the backcountry should be charged, not just those who sleep on the ground. Of course this is a rediculous idea but it does indicate (in my opinion) that a much more involved study should be undertaken. No one wants to see a toll gate at every trailhead!